Prelude Guy

All,

Curious if you guys can help me out. I have an engine that I'm hoping can be fixed. I'm hoping I can verify what caused it to break before I have it fixed, but before I do, I want to confirm why it failed so that it won't happen again once I have it all repaired.

I bought the car from someone who said while they were driving the car, it just randomly shut off. No sounds or anything. When I tried to start the engine, you could tell based on how easy of a time the starter had that there was low/no compression.

I took the engine out and took off the cam cover. The cam chain was broken on banks 1-3. I found the broken timing chain links in the oil pan. No other metal shavings in the pan. Oil looked fine, too.

I was doing some research and found two possible causes:
-The timing chain link could've failed. (http://flat6innovations.com/index.ph...es-illustrated)
-The scavenge pumps clogged up.

Any other possible causes I should look out for? Do I need to worry about anything thing else? Debris? I'm hoping it doesn't need a whole rebuild.

Also, any guestimates on how much I should expect to pay to get the valves replaced since they are more than likely bent? The engine is already out of the car.

Thanks in advance for the help!

Chris(MA)

You'll need to completely tear down this motor and clean it out very well.

The chain itself could have broken, or maybe the tensioner pads were worn out, some garbage in the scavenger pump also like you said could have caused the snapped chain.

I think you have to play it safe and assume you won't know what the initial cause is, only that you will need to check everything very carefully before a rebuild.

AnthonyGS

Bent valves will require a full head rebuild including guides. And if you rebuild one you need to do both so the engine will run optimally.

Flat6 Innovations

Very common failure these days.. 2002-03 3.6 engines are the worst for this..

I have proprietary master linked timing chains to address this without disassembly of the entire engine. Debris is generally contained within the cylinder head at the chain box area. If all debris is accounted for, a successful repair can be made. I have done this dozens of times.

The OEM Renold chains are poor quality, they stretch and lose rollers. I have a patent pending tool developed to measurechain stretch to help avoid this failure that's just as symptomless as an IMSB failure, but can cause even more damage.

Heres this week's broken timing chain... It was an IWIS chain from a 996TT, these are also failing at a high rate.

Looneybin

When these start to go, do they're make a chirping sound?

Flat6 Innovations

No. They don't "start to go". They snap all of a sudden.

It sounds like a shotgun went off behind you...

Hurdigurdiman

Flat6...Good to know as I have a chirping noise back left side of engine bay. Any idea where to look would be helpful. Thanks in advancce.

dporto

WP or one of the idler pulleys...if it's a chirping sound from inside the engine that can't be good...

europorsche914

Do you sell the chains for the DIYer? After investing in the ims solution, low temp thermostat and oil pump drive, Id be interested in eliminating one more failure mode..

Thanks!

Flat6 Innovations

I don't sell any parts, we use them for procedures.

Not sure if these will ever be available, no distributors want to jump on board to sell them, and pay me to share the procedure.

Nickshu

Oh joy, something else for me to worry about at my next track day.


I suppose I should adopt the "my engine is already dead" mindset and just drive it.

5CHN3LL

Back left side of the engine bay is the water pump, and "chirping" is the sound that a composite impeller makes when it scrapes aluminum...

Could also be an exhaust leak whistling.

If it was running poorly, I'd look for a spark plug that was only hand-tight, but that doesn't sound like the case.