"Taylor"

iTrader: (2)

On the way to rallyday at castle coombe i had my 2nd, in a few months, engine failure. The problem is suspected to be main bottom end bearing failure again. The engine was running in and had only covered 180 miles, with the previous engine having only covered 3000 miles before failing also. I was travelling at approx 65 mph on a fairly flat section of the motorway so there was very little load on the engine and no boost at all. The car is a 93wrx and the engine has been fully re-built and the spec list is as follows:

Spec C pistons
Eagle con rods
ACL big end bearings
ACL main bearings
New waterpump and elbow pipe from pump
New STI8 crank
Roger Clarke motorsport oil pump
Motorsport block liners
Reconditioned tappets
STI steel head gaskets
New Lambda sensor.

The first time it was rebuilt using my original closed deck block, but as this was thought to be the problem, the second rebuild was into a used block from a P1.
Speaking to the garage yesterday the clutch was thrown into question as it was said to be the common link between the 2 engines. The clutch is a few years old and has never caused problems before and as it's only a standard Exedy clutch i'm not convinced this could be the cause. Both failures have been on the motorway where the clutch hadn't been used for a while. I'm wondering if there is an oil pressure issue as the engines have both failed after running continuously for about 30 mins of operation. Fluids levels were checked before i left and were spot on and were also checked back at the garage and were fine apart from having little mettalic specs in the oil due to the failure.
I'm not looking to blame the garage, simply to assist them as i'm getting fed up of the engines failing. Any ideas and assistance will be greatly appreciated, especially from the experts, as i'm starting to loose faith.

Ringer4fun

iTrader: (1)

Bloody hell mate, is there no end to your nightmare, hope you get to the bottom of this problem.

John

Splitpin

Sorry to hear about your experience but our ability to diagnose will be limited here due firstly to not knowing for certain what the mode of failure was on thi second occasion. Most importantly, being able to physically see the broken bits will educate any guesses significantly.

Again without casting aspersions, let alone pointing blame, is "the garage" experienced in building engines (and Subaru ones in particular)? The thing that concerns me a bit is their suggestion that it might be the clutch because it's a "common link". That's clutching (no pun) at straws more than a bit, given that the clutch is external to the engine and cannot directly affect what goes on inside the block to any significant degree. Maybe, possibly, if it and/or the flywheel were significantly out of balance there might be some justification to the finger-pointing, but then if that was the case you'd probably feel the vibration, and as you say, you've had the same clutch for a number of years without it grenading your engine. The fact that the garage are coming up with ideas like this isn't the most confidence-inducing thing that could happen.

Some questions that might help us point towards answers: Was the RCMS oil pump new on this second build, or a carry-over from the first? If not, was it stripped and checked prior to incorporation into the new engine? What about the modene (oil cooler), was that new on this build or not?

Other questions that immediately come to mind (but that you may not be able to answer) include whether this ex-P1 block (and your old heads) were thoroughly cleaned prior to this build? Was oil circulation properly established prior to turning the engine over under compression (or starting it) for the first time?

Have you drained the oil yet? If so, have you still got it?

Sorry that there are more questionmarks than anything else in this post but unfortunately without the bits in front of us there's little certainty we can offer - hope what's above will help narrow things down a bit.

"Taylor"

iTrader: (2)

Thanks for the reply Splitpin, i'll try to answer your questions first. Yes the garage is experienced at building Subaru engines and is known to be a local Subaru specialist. A new modine was purchased along with the RCMS oil pump and both were carried over from the first build. I was told the block and heads were thoroughly cleaned previous to fitting and assume the same was done with the pump and modine. When the previous engine was built the mechanic quoted oil pressure's which had been achieved to me which were far above that of the standard oil pump, i can't remember these figures off the top of my head though sorry. I don't have access to the oil and i'm not sure if it's been drained yet. The tiny mettalic particles were spotted in oil from the dipstick when it was checked for this. The clutch was suggested as a possibility with the first failure as early blocks with the centre bearing apparently suffered occassionaly with "Crank walk" due to the clutch pulling on the crank when operated.
I know any ideas and suggestions will be speculative, but i'm hoping it could throw up a few ideas i haven't though of.

mit

iTrader: (10)

I thought it was common place to replace the modine after a failure, due to metal partical contamination? If it was re-used, wouldnt it put those particles into the new oil?

fastmike

iTrader: (4)

So the common parts to both engines are the oil pump and modine ?
there might be a clue there mate

Ste RB5138

That is such bad luck, there is something seriously wrong for it to go after 180 mile!

I hope the garage sort it out for you.

Splitpin

Hmmm. Hope that assumption doesn't turn out to be ill-founded. Oil pumps can be stripped pretty much entirely (do you know if it was, or simply flushed?), but modenes, best practice is normally to replace as a precaution. These two seem more likely contributors to the failure than the clutch, if common factors were being looked for.

Do you know whether there was any pickup on the thrust surfaces of the old centre bearing and crank that might support this? Either way, shouldn't be an issue with the newer rear thrust setup that's gone this time.

Is the same garage going to be stripping and examining this engine?

scubbay

iTrader: (61)

Theres no way I'd ever re-use a modine after bearing failure. The fact that it "was new" on the last engine means nothing. I believe they could never be flushed 100%. Bad luck mate its a sickening feeling I know.

m@t STImulation

iTrader: (3)

i know how you feel i had a 2.5 cracked the block the a ej20 and then again another ej20 in the space of 6 months the 2.5 was like it when i got it i rekon.

the money we put into them! mine obvi runs into the ££££ for a basicly standard car :-( 300bhp,
when i had the second block, i went to see jollygreenmonster he installed a running-in map for me. he was able to tell me if the engine sounded correct, in regards to noise etc. that's the only advice i could give you
JGM diagnosed the 1st ej20block as a potential failure, and this turned out to be rounded cam bolts 5 in total!! needles to say wont be using that garage in sittinbourne every again.

all sorted now big thanks to JGM and AW motorsport

Brett_555_Sti

iTrader: (18)

If they say the clutch is the common part between the 2 engines running bearings, I would say they should not even be working on lawn mowers, they should have checked crank end float to start with, that in itself will not exactly cause big end failure as the gudgeon pins are fully floating and will not put stress on the big ends as such.

There are alot of people out there running uprated clutches(with stiff pressure plates) and alot more power than it sounds like you are running and their engines last a good while.

As above- the problem is most certainly the modine oil cooler, without a doubt, they cannot be cleaned successfully, no matter what method you use.

Oil pumps can be cleaned, but they need to be measured and compared against the maximum allowable tolerances/specifications, if the pump is scratched I would relace it, no matter how many miles it had done.

Another thing is are they doing the prep work correctly, checking clearances, cleaning etc... Because its new or just come back from the machine shop does not mean its right, clean and ready to put together, that is what plastigauge, putty and elbow grease is for.

What oil was used for the first start up and run in?

stuart2008sti

iTrader: (1)

Mine did the same thing at 330 miles after rebuild,they could not tell me how or why it had failed only that it had.bigends went and trashed the whole engine.Hope you get this dealt with .

TonyBurns

iTrader: (3)

Why do people carry on using an oil pump and modine from a previous engine failure these just help kill your second engine by the sounds.
When rebuilding your engine, you must, note MUST replace everything that oil flows through as this carries debris from any other component failure.

If your going to get it rebuilt again, ensure nothing old is used, ask for ALL the parts back as they are yours anyway.

Tony

"Taylor"

iTrader: (2)

I'm not sure to what level the oil pump was cleaned and if the modine was replaced or just cleaned, but it makes sense for it to be replaced. The same garage will be stripping the engine as the warranty is with them.

Agreed with the clutch issue, i'm not buying that either. Its only a standard Exedy, not even the organic type and the car isn't running big power, 330BHP at my last run at Powerstations rollers. As for the oil, a 10/40 semi synthetic was used for the running in at least, and the initial startup.

So everybody seems to be leaning towards cross contamination from the Oil Modine then.

Brett_555_Sti

iTrader: (18)

The other common part will be the injectors, doubt its that, but its worth a check.

Remove the sparks plugs and check if the colours on the tips around the electrode are all the same, should be a light brown colour.

If you have one that is a different colour to the rest you may have a problem with an injector.

"Taylor"

iTrader: (2)

This does seem to be a common opinion, and is certainly something i will be asking about when i speak to the mechanic.

"Taylor"

iTrader: (2)

The car is at the garage at the mo. I thought an injector problem would lead to piston damage due to running lean, not to bearing failure though?

Brett_555_Sti

iTrader: (18)

A hard enough knock from detonation could "squash" the bearing.

Butty

iTrader: (2)

It would be in your interest to hire an independent assessor off your own back when this is being done.
the warranty co. may be relying on the garage themselves to report the failure and given their dubious response so far, I would be a little wary.

Splitpin

Can't disagree, have had a bad feeling about this from the outset that has got worse as more info has emerged.

At least it's under warranty, which is one good thing. May even be worth contacting the warranty company yourself and asking them if they'll provide an engineer to observe the teardown. An engine that suffers major bearing failures after less than 200 miles raises obvious questions about the quality of the build. Allowing the garage to effectively mark their own work doesn't look like the best way forward at this point.

HRT

Is the 10w/40 semi synthetic suitable for running in? I thought a mineral based oil was needed.

The Stitcher

iTrader: (12)

Taylor cant believe this has happened again... would you like me to build it for you?

Cannon Fodder

iTrader: (100)

Taylor have you heard anything back yet from the garage in question?

I am sure Moose will lend you his car if you feel the need for speed.

dj219957

is it running a standard ecu and standard boost or is it running as chip of some sort?

"Taylor"

iTrader: (2)

The warranty is with the garage itself, not an independant company, so them stripping it is the only option, unless i decide to take it elsewhere, but i doubt they'll honour the warranty then.

I can't believe it either Lee, starting to loose faith now, gutted as i love the car so don't want to get shot of it, just need a reliable engine.

No, the car has an Apexi ECU, mapped by a well respected Scottish mapper. I can't see the ECU causing the problem though as the engine wasn't even running boost for fueling to be an issue. Doesn't the Lambda sensor refine the fueling when the car is in cruise?

The car originally went in as it had blown a piston ring land due to the standard pistons not being able to cope with 1.5 bar of boost. I opted to have a fully forged rebuild to make sure it was reliable to run this level of boost. Can't believe i'm having all this trouble, its not exactly running big power compared to most.

Butty

iTrader: (2)

Even more reason for an independent assessor to be on hand when its split open.

Splitpin

Really? Wow that's a bit, ummm, incestuous. Silly question maybe but do you have a policy document from them stating exactly what the terms of this warranty are? Are you certain that they're actually underwriting this themselves and aren't covered by a third party insurer?

Was this ECU mapped on the original engine (the one on using your original CDB) or was it remapped after you had the P1 block engine? I'm guessing not seeing as you only had that one in 180 miles.

Does the Apexi use the lambda in cruise mode? Either way, if you've transferred an ECU from one engine to another, you can't guarantee that a map that was safe on the first will be equally so on the second, even during cruise. Indeed, the garage might also try and suggest that even though the failure became noticeable when you were cruising, it was shoe-down driving prior-to that initiated it.

It's to cover eventualities like this that you could really do with an impartial engineer present when the engine is examined, especially on the assumption that this warranty contains an exemption clause for "abuse" or similar. Given the potential consequences of the garage trying to set up a situation where they can say that the warranty (they apparently provide) doesn't apply, it probably is worth the precaution on your part.

bluerigster

iTrader: (9)

Sorry to hear about your engine troubles hopefully the warranty will cover the rebuild.

Was the crank movement measured on the CDB using a dial gauge on the front crank pulley to determine whether there was movement?, as without shell bearing clearance issues I can't see crankwalk on a 3000 mile motor being an issue as you would have noticed a difference in your clutch pedal engagement height!. Also why didn't they opt for a rear thrust conversion on the CDB for the second build?, as running dual thrust bearings on the 3rd and 5th journels would make for a more reliable engine over a sleeved semi CDB. Was the P1 block chemically cleaned and all oil supplies brushed to remove a partial blockages prior to the rebuild?.

With the new build was the oil changed straight after originally running the engine up for the first time and the oil filter changed?. Also how many times in total has the oil been changed and are you using a magnetic sump plug and if so what was your findings?. Also was the sti 8 crank new or a regrind and if so by how much was it reground?.

"Taylor"

iTrader: (2)

I spoke to the mechanic today and he confirmed that the crank and bearings were destroyed, he said it was almost as if it had run out of oil, even though when checked the oil level was fine. He said he's a bit stumped as to why it had failed. I asked about oil pump and modine and he said a new modine was used on each rebuild and as the pump was a brand new Roger Clark item it was cleaned thoroughly and re-used. I'm not sure wether the crank was new or not. The engine was initially started up and run up to temperature, then the oil was changed, then it was run for a while, then the oil was changed again. He did suggest converting my original CDB to have a rear thrust bearing also, as he had seen this set-up on a WRC engine he had stripped, but could not find anyone to do the conversion. I'm going down to meet with him at the garage Saturday, to have a better look at it myself.

merlin24

iTrader: (1)

The back of the big end and main bearing shells will be stamped STD or an over-size, that will tell you if the crank is standard or a re-ground one.

Also ask the garage if they removed the oil restrictor from each cylinder head and thoroughly flushed the oil gallery's in the heads before refitting the restrictors.
Bearing debris from an engine failure can get trapped in the heads and subsequently be circulated through a newly rebuilt engine with obvious consequences.

Hope it all works out in your favour at the end of the day tbh

Mick