The real reason people are breaking rods

[cpolly69]

[QUOTE=djuosnteisn;318741]If this were the case, wouldn't you expect to see the blow trend favor the more highly modified cars, rather than randomly thrown rods across the whole platform?

Cylinder #3 flows better then the rest and #1 flow the least - I think if we really knew what was going on we would see more #3 then anything else -
- Yesterday I sat down and tried to scan through the blown engine resource thread and count the blow ups and what cylinders they were on and I came to some conclusions -
1. The majority of the ones on there are listed as "unknown"
2. A large number of them say 2 rods - If that's all it says you can only assume it's the one that comes first in the firing order
3. There still a good number of #3's on there and I think if you really knew the rest you would see #3 was the majority
So to answer what you asked - The intake mani is a pos in stock form - It's a pos if you have just an intake or if you are fully bolted - as long as you're still running it w/out it being flow matched the harder you push the engine the more you roll the dice

[Lex]

Originally Posted by djuosnteisn If this were the case, wouldn't you expect to see the blow trend favor the more highly modified cars, rather than randomly thrown rods across the whole platform? I'm to the point where i just don't want to replace a blown engine. It's become too real of a possibility lately. So fuck it, if the rods are what keeps breaking, pauter here i come. I still believe there is an unusual reason for our misery, but i don't like the idea of just sitting here while we all come up with one wild idea after another. I'm sure we'll eventually figure out what the problem is, but i'm just not down to be one of the test samples. Lex, if you want me to send you 4 good stock rods in the coming months for analysis, i'll def do that, but don't be offended when i say i don't want to send you a broken one.

Are you doing pistons too? If keeping stock pistons, I'd get the Carillo rods.

[djuosnteisn]

All up in there air honestly. I've already put so much in the car that going back to stock really isn't top of my list, but still i'd feel incredibly stupid if i threw a rod.

Putting more money into the car with such a low cap in power isn't exactly a glass half full either.

I guess i'm just venting more than anything, lol. We'll see what i decide.

[mituc]

Actually what were the peak levels of torque of those engines that threw rods out and at what RPM?
++what was the engine speed and how much was the throttle opened when it happened?
Of course, a list of mods is also important, it is possible (even though unlikely) that some aftermarket parts or combinations of them to lead to such problems (overheating, poor lubrication or engine oil degradation, ECU maps running the engine way too lean making it to overheat, and so on).

I've been looking through all these broken rods threads for a while and I coundn't find any usable information , not even "stay stock!" because we've also had people saying that they broke rods with a stock engine and stock ECU map - come one!, I'm not sure that they've said that just in case their Mazda dealer will identify them on a forum based on their nick names (it wasn' me! Just someone pretending that it's me - end of story).

[shpankey]

Originally Posted by mouse0330 oh boy, after reading a couple of pages in this thread...then I have to skip to the last page because you guys start to turn a good thread into a shit....Ladouche needs to stop posting up csrt4/bmw dynos and graphs and shit...can't compare this 2, there aren't many caliburs out there anyway. back to the thread, I just got an AP from corbs, install the new denso plugs, load up stage 1 93 map....then I got kr like crazy around 3k rpm, a lot of hesitation/like boost lose..occur when kr... my car before all this have 56k miles runs like a charm, last dyno have huge torgue with only 268whp....and about 320 tq, 56k with original oem FOMOCO spark plugs..lol until now, after installing the AP...run like shit...literally like shit, will give a try longer with diff maps and see. been monitoring everyday and it seems Lex is on to something, I do get kr around 3rpm no matter what gear, lately more so on 5 n 6. I have cobb sri/inlet/ap/ and ets tmic for power mod..

Did you add the HPFP internals like COBB recommends? Just curious. They seem to be saying that you should not do the AP at all until you get this done. Kind of sounds like you were getting fuel cut. A HPFP upgrage should fix that.

[jellowood]

Wow. After reading all this I'm really having second thoughts in purchasing a CAI/SRI on my new MS3.

[DaleNixon]

I've heard of a lot of cars blowing stock but can anyone point out a single verified example?

[BudUMfan]

Originally Posted by jellowood Wow. After reading all this I'm really having second thoughts in purchasing a CAI/SRI on my new MS3.

Just do what Lex said, be smart, and you should be fine....or you could blow.

[jellowood]

Originally Posted by DaleNixon I've heard of a lot of cars blowing stock but can anyone point out a single verified example?

And if they were stock are they all 1st gen or any from 2nd gen?

[06Speed6]

Stock lawnmower engines blow sometimes, its not a big deal unless its alot of them. There are very few cases where any gen of the stock engine blew and some of them had been hydrolocked. According to Mazda, an unmodded engine without defects should never blow and after tearing into this engine and going through it like I have, I am inclined to agree.

Ive been of the opinion for a while that you have to replace nearly everything on this car for it to be reliable at higher hp levels.

[bf360]

This thread is really scaring the newbs lol

[jellowood]

Originally Posted by bf360 This thread is really scaring the newbs lol

Nah not at all


Hey hun..... Where's my old bicycle at??? J/K

[Matrix311]

Originally Posted by jellowood Wow. After reading all this I'm really having second thoughts in purchasing a CAI/SRI on my new MS3.

I wouldnt worry about it. There are thousands of these cars on the roads with a limited amount of horror stories. You can go to any car forum and see the same results.

I've had all the mods in my sig on my car for 45,000 miles and not a single issue. My car runs just as strong as the day I modified it.

[Mazdanspeed3]

jah to that ^.. mine is fine. lol

[dizzin9]

Originally Posted by DaleNixon I've heard of a lot of cars blowing stock but can anyone point out a single verified example?

+1

[ptperformance]

Originally Posted by Lex I have looked a lot at these blown engine issues. In the end it was all under our noses. The rods are plenty strong for this application and I have compared them dimensionally to both EVO X and SRT4 rods. They are no lighter and although the bolts are a mm smaller in diameter, the DISI engine was not designed for high RPM and we are not breaking rod bolts. I have looked at binding issues, hydrolock etc ... nothing was concrete. So then I looked at the rod construction and noticed the small end is tapered. Interesting. Diesel engines taper the small end so that the bearing surface is lower so that the rod takes a high load. The rod I have seems to have some good wear on the bottom of the bearing caused by cylinder pressure. Interesting. Perhaps poor oiling. Perhaps too much pressure. I then looked at how similar cars produced power and as it turns out no EVO or SRT4 motor makes as much torque as we do at such low RPM. Period.

Took me all of 5 minute to find a dyno of an SRT4 that made more TQ that the MS dyno you posted, so doesn't look like you tried very hard.

[ptperformance]

Here is another one, so much for that "period" in your comments.

This is an SRT4 dyno with the S3 turbo on it and its making over 400 TQ before 3500 RPM. I will see if I can find some stock turbo dyno's where guys are making 350 WTQ at 2500 RPM. Hang-on I will see what I can come up with.

[ptperformance]

Last, the creme of the crop, just one of the many SRT4's we have tuned on the stock turbo making 375 WTQ before 3000 RPM and the car is still running strong. So much with the SRT4's not making TQ like the Mazdaspeeds and that being the cause of the problem. I cannot wait to hear what the next great idea is.

[kore2000]

The SRT4 may be making as much or more HP, but what about midget power. The MS3 kills the SRT in midget power..and that's why we are breaking rods.

[ptperformance]

Originally Posted by kore2000 The SRT4 may be making as much or more HP, but what about midget power. The MS3 kills the SRT in midget power..and that's why we are breaking rods.

Look at the dyno charts, they are making more TQ than the MS down low. The SRT4 doesn't have a problem with breaking rods with making TQ like this. I would also be willing to bet that the EGT's and cyl pressure are higher than that of the MS.

Not only that but the last dyno shows 300 WTQ at 2500 RPM and its making 100 WTQ more at 2500 RPM than the dynos Lex showed as a reference, how much more midget power do you want?

[kore2000]

Originally Posted by ptperformance Look at the dyno charts, they are making more TQ than the MS down low. The SRT4 doesn't have a problem with breaking rods with making TQ like this. I would also be willing to bet that the EGT's and cyl pressure are higher than that of the MS. Not only that but the last dyno shows 300 WTQ at 2500 RPM and its making 100 WTQ more at 2500 RPM than the dynos Lex showed as a reference, how much more midget power do you want?

Depends on the strength of the midget. A strong one could be twice as powerful as a weak one.

[ptperformance]

Originally Posted by kore2000 Depends on the strength of the midget. A strong one could be twice as powerful as a weak one.

Are we talking a real midget like dwarf size or mini people?

[kore2000]

Originally Posted by ptperformance Are we talking a real midget like dwarf size or mini people?

Well for a big turbo build you need the ones at the circus with all those mini muscles, for a DD, just regular midgets will do.

[ganque]

So...
Is this bad? or normal?

[Lex]

WTF is this cluttering this thread? The rods in the DISI motor are not designed to handle the kind of torque the SRT4 rods do. Mopar has always made strong, although brute force, motors.

Take it as you may, torque spikes, boost spikes, and detonation are what kill the DISI and they are related.

Ganque, if you're not seeing excessive KR, you're good to go. Dyno looks good.

[FORZDA 1]

Here's a link to 6club where I'm working with a Speed6 to diagnose/fix what seems like several problems. IMO, it definitely has a tweaked rod(s) from one or more severe detonation events. The base timing is bouncing +/- 3-4 degress at steady idle (viewed on the AP) so it definitely has some basic timing control issues. Got a call last night and he said that Mazda had pulled the plugs and found one with oil on it. Couldn't confirm whether the oil was on the firing tip or just around the threads, so hopefully I'll have some first-hand inspection info to bring back to the group...


Unfortunate (Rod?) Noise..... - Mazda 6 Forums : Mazda 6 / Mazda Atenza Forum

[Lex]

Originally Posted by FORZDA 1 Here's a link to 6club where I'm working with a Speed6 to diagnose/fix what seems like several problems. IMO, it definitely has a tweaked rod(s) from one or more severe detonation events. The base timing is bouncing +/- 3-4 degress at steady idle (viewed on the AP) so it definitely has some basic timing control issues. Got a call last night and he said that Mazda had pulled the plugs and found one with oil on it. Couldn't confirm whether the oil was on the firing tip or just around the threads, so hopefully I'll have some first-hand inspection info to bring back to the group... Unfortunate (Rod?) Noise..... - Mazda 6 Forums : Mazda 6 / Mazda Atenza Forum

Forzda, glad to see you're looking into this car. I myself have "bouncing timing" between 9-11 degrees at idle. This has happened after I increased my idle speed to 850 RPM AND installed an oil catch can that has a very minor leak (poor welds ) There are no driveability issues and I've had this condition for over a year. LTFTs are steady throughout so I never delved in the issue further.

The leak at the MAF sensor could have caused the hunting timing. It certainly sounds like the violent detonation events caused one of the rods to bend which now likely has pretty severe blowby (hence the oil). Were you monitoring AFR during those WOT runs?

[FORZDA 1]

Originally Posted by Lex ...... Were you monitoring AFR during those WOT runs?

Unfortunately, no. He was watching KR on the AP which he had mounted such that you had to look down and take your eyes off the road to see it. He saw a solid 5.8 at WOT/high revs, but we didn't get any data logged before hearing the knocking and called it off.

The car still seems to run reasonably well at part throttle and he drove it home and back to the dealer who changed out the timing chain/tensioner. He was to drive it home again last night as well.

The noise isn't real loud, but it is definitely a deep crank-level knock. It isn't the classic rod bearing noise: knock, knock, knock, double-knock. It is a single knock in time with engine rpms. At first I thought it was the piston bottom lightly hitting the crank counter-weight, but if so it likely wouldn't have survived this long. I think we caught the damage before the rod bent so bad that it fully collapsed into a zoom, zoom, boom event, but... if there is truly oil on the plug tip, the piston may be scored/damaged as well.

[Lex]

Originally Posted by FORZDA 1 Unfortunately, no. He was watching KR on the AP which he had mounted such that you had to look down and take your eyes off the road to see it. He saw a solid 5.8 at WOT/high revs, but we didn't get any data logged before hearing the knocking and called it off. The car still seems to run reasonably well at part throttle and he drove it home and back to the dealer who changed out the timing chain/tensioner. He was to drive it home again last night as well. The noise isn't real loud, but it is definitely a deep crank-level knock. It isn't the classic rod bearing noise: knock, knock, knock, double-knock. It is a single knock in time with engine rpms. At first I thought it was the piston bottom lightly hitting the crank counter-weight, but if so it likely wouldn't have survived this long. I think we caught the damage before the rod bent so bad that it fully collapsed into a zoom, zoom, boom event, but... if there is truly oil on the plug tip, the piston may be scored/damaged as well.

It takes very little tweaking to have the piston touch the counterweight. The aluminum on the piston being soft wears off pretty quickly and you should be able to see the marks from under the car with the oil pan removed. With a bent rod, the piston is no longer square in the bore and rod is plastically deformed. This places a lot of stress on the already deformed and weakened rod even during non WOT driving so I would not start the car period for the sake of saving the block.

I am very curious what went on during the test drive - if it was a lack of fuel or timing related ... or a boost spike.

[FORZDA 1]

Originally Posted by Lex ....... I am very curious what went on during the test drive - if it was a lack of fuel or timing related ... or a boost spike.

Yeah me too! I really think it was timing related, but obviously can't be positive as there is no logged data. As I read around the forums, it seems the OTS maps aren't quite right as most people don't run exactly what's specified for the map as far as mods. I'm not going to declare the OTS map the problem as the car definitely had timing chain/tensioner problems before the event that could have set the stage for the "big" event.

Unfortunately the guy didn't have anything other than the AP for gauges, so it is all terribly unfortunate (for him and us), but more knowledge will definitely come from it so maybe a positive outcome in the end....

[SSinstaller]

My timing is not static at idle either. I have never worried about it..

Just checked it.. Fully warmed up timing advance is sits around 9~11 mostly, but it will occasionally bounce as low as 7 and as high as 12.. My CKP sensor currently has a coating of oil which my account for the larger low and high bounces, but even on the OEM motor I never recall it sitting exactly at 10 like the FSM says it should..

My Idle sits in the mid to high 800's with the Cpe Flashes..

[ptperformance]

Originally Posted by Lex WTF is this cluttering this thread? The rods in the DISI motor are not designed to handle the kind of torque the SRT4 rods do. Mopar has always made strong, although brute force, motors. Take it as you may, torque spikes, boost spikes, and detonation are what kill the DISI and they are related. Ganque, if you're not seeing excessive KR, you're good to go. Dyno looks good.

I then looked at how similar cars produced power and as it turns out no EVO or SRT4 motor makes as much torque as we do at such low RPM. Period.

What? I have quoted your very first post ^^^ and I have proven that wrong. You made a basis on the SRT4 rods, the EVO rods, and the Mazda rods and you said:

The rods are plenty strong for this application and I have compared them dimensionally to both EVO X and SRT4 rods. They are no lighter and although the bolts are a mm smaller in diameter, the DISI engine was not designed for high RPM and we are not breaking rod bolts.

Sounds like your starting to back track from your very first post. So what is it, are they strong enough or are they not? Are they similar to those of the other rods you compaired them to or... are they not?

I find it funny how you consider this clutter in your thread but when I bring forward the "facts" all the sudden my proof becomes clutter. TQ spikes and boost spikes are not what "kills" the DISI motor, its a one time event in most cases that causes the damage. Some might get it a little at a time, others get it all at once, but I can tell you from "first hand experience" it is a single event that causes all the damage not abuse over time.

Originally Posted by Lex Forzda, glad to see you're looking into this car. I myself have "bouncing timing" between 9-11 degrees at idle. This has happened after I increased my idle speed to 850 RPM AND installed an oil catch can that has a very minor leak (poor welds ) There are no driveability issues and I've had this condition for over a year. LTFTs are steady throughout so I never delved in the issue further. The leak at the MAF sensor could have caused the hunting timing. It certainly sounds like the violent detonation events caused one of the rods to bend which now likely has pretty severe blowby (hence the oil). Were you monitoring AFR during those WOT runs?

You are assuming that the car was started after the rod bent which allowed the blow by, but what if the rings are still sealed on the cyl walls then what would cause the oil build up in the cyl's? Bent rods will not all the sudden allow oil into the motor unless the ring seal was comprimised.

[Lex]

Originally Posted by ptperformance What? I have quoted your very first post ^^^ and I have proven that wrong. You made a basis on the SRT4 rods, the EVO rods, and the Mazda rods and you said: Sounds like your starting to back track from your very first post. So what is it, are they strong enough or are they not? Are they similar to those of the other rods you compaired them to or... are they not? I find it funny how you consider this clutter in your thread but when I bring forward the "facts" all the sudden my proof becomes clutter. TQ spikes and boost spikes are not what "kills" the DISI motor, its a one time event in most cases that causes the damage. Some might get it a little at a time, others get it all at once, but I can tell you from "first hand experience" it is a single event that causes all the damage not abuse over time.

So John - is it a one time, or a little over time? Make up your mind buddy - at this time you're agreeing with me. Where's the hydrolock BS or are you done defending that?

Boost spikes = TQ spikes = detonation in this 9.5:1 motor that overwhelm stock rods. Low RPM exacerbates the situation since the gases have more time to heat and detonate.

So ...umm... what's your point? Still trying to sell your PCV system that will fix it all? IF hydrolock was true, how is your system going to fix this anymore than a CC???

[ptperformance]

Originally Posted by Lex It takes very little tweaking to have the piston touch the counterweight. I am very curious what went on during the test drive - if it was a lack of fuel or timing related ... or a boost spike.

How much tweaking? .200? .500? ????

Which one would cause the rod to bend, I mean come on.... its either boost spike, TQ spike or detonation that causes these to blow. You need to pick a problem and find a solution for it. If that solution doesn't work move onto your next solution and so on and so on. This is how problems are fixed in the performance world, sitting around and talking about it all day does nothing to resolve the issue.

[ptperformance]

Originally Posted by Lex So John - is it a one time, or a little over time? Make up your mind buddy - at this time you're agreeing with me. Where's the hydrolock BS or are you done defending that? Boost spikes = TQ spikes = detonation in this 9.5:1 motor that overwhelm stock rods. Low RPM exacerbates the situation since the gases have more time to heat and detonate. So ...umm... what's your point? Still trying to sell your PCV system that will fix it all? IF hydrolock was true, how is your system going to fix this anymore than a CC???

I don't know, you need to tell me (insert sarcasim), LOL.

Boost spikes = TQ and since we don't see the TQ fall off in the dynos that would mean there is no detonation (big hole in that idea). What happened with all the research that you did in compairing the rods? What happened to the "period" commnet that SRT's done make as much TQ as the DISI motors down low?

NO!!! What is your point, what is your idea on how to fix this? At least we have something that we are working on something to address the problem, you have ??? what again?. At least we have first had experience with tearing down multiple motors that have blown and "proof" of the oil in the cyl's and the rods indicating that they were in fact hydrolocked. How many motors have you torn down?

A CC will stop some of it, but how many good catch cans are on the market that are divided with filter media in them. The simple CC's that just have two fittings side by side are doing nothing to trap the oil vapors in the can and they are still getting sucked up into the intake. Last... how do you explain those cars running with CC's getting all the oil build up inside the intakes as well as carbon on the back of the intake valve? The EGR system will not do this because there is not enough oil/carbon to cause raw oil to show up inside the runners.

Our system is addressing the issues with the location of the PCV and blocking the port on the front of the motor that causes all the oil evac into the intake manifold. What does your fix intail?

[knarfies]

well my only worry is im installingmy cai today with the hydro shield. I may have read too fast or not enought but i dont want my car blowing.

Yes ima noob

[ptperformance]

Originally Posted by knarfalvarez well my only worry is im installingmy cai today with the hydro shield. I may have read too fast or not enought but i dont want my car blowing. Yes ima noob

You have nothing to worry about, drove it like you stole it and you will never have any worries. Drive it like grandma and WOT in 6th gear at 35 MPH (please video this for us) and you might have some major issues.

[knarfies]

"Drive it like grandma and WOT in 6th gear at 35 MPH (please video this for us) and you will have some major issues.
"

lol please explain.

[gtarman77787]

^^ knarf -- donate.... also, when you're driving in 6th gear going about 35 or so, its always good to go WOT to clean off the spark plugs so you dont get a p8393 (spark plug failure code)

okay okay .. i kid i kid... WOT @ 35mph = too much torque at too low of an RPM... thats when your car likes to not respond and cut off fuel (from what i think i understand)

either way... DONT DO IT
ITS BAD
YOU WILL BOOM

[djuosnteisn]

If oil vapor is doing anything at all, its simply lowering the octane of the fuel mixture and increasing likelihood of detonation.

Cruising on the highway merely creates an extremely hot combustion chamber, and increases the likelihood of detonation.

For a motor to hydro lock on oil, it would take a complete failure of the PCV system, and probably badly worn rings.

We all know that detonation kills any motor. And we also know that these motors like to detonate. Is it really that hard to conclude then, that detonation kills these motors?