Car died on highway today. Possible timing belt?

[mattg1.8]

I was merging on the highway today revving it out pretty good and at about 6000 rpm it stopped revving and the red oil light flashed on the dash and it started running really rough and the brake pedal got stiff and was tough to stop. I pulled over and the idle was jumping around and would barely run. Got her towed home and checked for any obvious signs of damage and didn’t see anything. I pulled the 4 easily accessible plugs and all looks normal. The check engine light never came on and theres no codes popped when i scanned it. I’m thinking it jumped a tooth or possibly bent a valve? Are these engines susceptible to jumping timing? I have a video I’ll work on getting it uploaded. Any help is appreciated. Thanks.

[mattg1.8]

https://youtu.be/qf6TpQ7Mr9s

[ActiveMonkey]

Have you checked the intercooler hoses? When my lowers pop off it "runs" very much like that and for get about driving it.

[mattg1.8]

Have you checked the intercooler hoses? When my lowers pop off it "runs" very much like that and for get about driving it.

Yea I checked them all they all look to be attached, I’ll check for any holes in the hoses today

[christianb5s4]

Unplug your MAF sensor and see how it runs, if it runs better that confirms a boost/vacuum leak. If not then we will move to next steps.

[mattg1.8]

Unplugged the maf and it ran a little rougher than before then stalled and will not restart

[mattg1.8]

Got it pulled apart to check timing. I put the passenger cam with silver oval facing inboard with the larger hole. It looks like the driver side could be off a tooth???

[ActiveMonkey]

how is the tension on the belt? Can you cycle the engine?

[VR6Bomber]

Compression test?

[mattg1.8]

how is the tension on the belt? Can you cycle the engine?

The tension feels normal, not overly slacked at all

[mattg1.8]

Compression test?

Haven’t done a test yet, I will do one this weekend.

[mattg1.8]

Did the compression test today. Got 0 lbs on cylinder 4. All others are normal, between 145-165. The plug on the right is the one that came out of that cylinder.

I assume it’s at least one bent valve but not sure what the extent of the damage in that cylinder will look like. Bummer.

[ActiveMonkey]

Damn, sorry to hear that.

[VR6Bomber]

Did the compression test today. Got 0 lbs on cylinder 4. All others are normal, between 145-165. The plug on the right is the one that came out of that cylinder.

I assume it’s at least one bent valve but not sure what the extent of the damage in that cylinder will look like. Bummer.

I have a set of heads that I just removed from a working motor if you are interested

[SoundEfx]

I feel your pain. When this happened to me, I had 0 pressure in 4 cylinders not cylinder 4.....lol...
The failing part was not the tensioner, but the tensioner pulley. So don't skimp out (not saying you would) on the replacements parts because you never know what will fail.

Just be careful with the 'While it's apart, I should replace .......' syndrome because you might some how end up buying new rods.....lol

[mattg1.8]

I feel your pain. When this happened to me, I had 0 pressure in 4 cylinders not cylinder 4.....lol...
The failing part was not the tensioner, but the tensioner pulley. So don't skimp out (not saying you would) on the replacements parts because you never know what will fail.

Just be careful with the 'While it's apart, I should replace .......' syndrome because you might some how end up buying new rods.....lol

Hahaha yea I’m already plotting what I should replace. I haven’t pulled it apart yet but should I be expecting piston and cylinder damage or probably limited to the head and valves only?

[mattg1.8]

I have a set of heads that I just removed from a working motor if you are interested

Sweet man thanks I may be looking for them depending what I find when I pull it apart

[VR6Bomber]

Sweet man thanks I may be looking for them depending what I find when I pull it apart

I have stock used pistons as well. You'll probably need one piston for that cylinder that made valve contact.

[SoundEfx]

I'm telling you man, it's slippery.

" Well the engine is apart and I'm replacing a piston, might as well beef it up with some rods."
" Well the bottom end is beefy, I might as well get a bigger turbo."
" Bigger turbo means it needs to breathe, might as well get 'head work'. "
" Damn, I have way more power, need a tune. "
" Damn it.. now I need a new clutch to hold this power."

" WTF?!?!?!?! All I should have done is get the ONE piston and new head."

LOL......

[VR6Bomber]

I'm telling you man, it's slippery.

" Well the engine is apart and I'm replacing a piston, might as well beef it up with some rods."
" Well the bottom end is beefy, I might as well get a bigger turbo."
" Bigger turbo means it needs to breathe, might as well get 'head work'. "
" Damn, I have way more power, need a tune. "
" Damn it.. now I need a new clutch to hold this power."

" WTF?!?!?!?! All I should have done is get the ONE piston and new head."

LOL......

My favorite is;
Well, Since I have the the motor is out...

[projectvoltron]

My favorite is;
Well, Since I have the the motor is out...

Gets me every time

I got my brother into the b5 s4 platform and he is starting to come around to this thinking also.

Its a slippery slope that leads to glory and bankruptcy

[mattg1.8]

Lol I can see it all happening, I’m going to refrain from those thoughts until it’s apart and I can assess what’s goin on. Should have it apart this weekend.

[projectvoltron]

I hope its just a bent valve so you don't feel compelled to take the block apart

[mattg1.8]

I hope its just a bent valve so you don't feel compelled to take the block apart

I hope so too man, but 0lbs of compression makes me think the worst.

[projectvoltron]

I hope so too man, but 0lbs of compression makes me think the worst.

I had a forester xt that bent a valve and It had 0 psi compression

Fingers crossed for you man!

[mattg1.8]

Got the intake manifold off today and can clearly see the middle intake valve is bent and not moving when the engine is turned over. Should be pulling the head this weekend to check the piston damage. I took a video of the cam chain tensioner though because it seemed pretty jumpy. Is this normal for turning the motor over by hand? Also, should the cams be straight up and down in line with the arrow on the cap when at tdc on cyl 3?



https://youtu.be/l-pfU7VuUGs

[projectvoltron]

The cam chain tensioner works off of oil pressure. So when there isn't much oil pressure it becomes less rigid.

[evilgti84]

from that video you posted, your chain tensioner is shot on that cylinder head. would recommend you replace both of them

[projectvoltron]

I retract my previous statement...

I didn't see your video.

Definitely have a shot cam chain tensioner.

That's the same head that it appears to have skipped a tooth correct?

[mattg1.8]

I retract my previous statement...

I didn't see your video.

Definitely have a shot cam chain tensioner.

That's the same head that it appears to have skipped a tooth correct?

Yes, thats the same head with the bent valve. Im pulling the head on that side but wasn't planning to pull the passenger side, can i replace the tensioner on the other side without removing the head? It actually looks like the skipped tooth might have been on the passenger side (not the one with the bent valve). With the crank lined up the driver side (bent valve) cam ring is perpendicular and the passenger sides is off by about a tooth.

[projectvoltron]

Yes, thats the same head with the bent valve. Im pulling the head on that side but wasn't planning to pull the passenger side, can i replace the tensioner on the other side without removing the head? It actually looks like the skipped tooth might have been on the passenger side (not the one with the bent valve). With the crank lined up the driver side (bent valve) cam ring is perpendicular and the passenger sides is off by about a tooth.

That's a little odd that the side that didn't skip a tooth is the one with the bent valve.

You can replace the tensioner without removing the head or even the timing belt. But you're way past that point

https://www.audiforums.com/forum/diy...g-belt-174109/

[jcarruth]

Tial 770 build while the motor is out or???

[projectvoltron]

Tial 770 build while the motor is out or???

TTE 1200

[mattg1.8]

Tial 770 build while the motor is out or???

Lol I haven’t pulled the motor I’m popping the heads in place. Don’t give me any ideas!!
But do you know someone selling a kit........?

[mattg1.8]

That's a little odd that the side that didn't skip a tooth is the one with the bent valve.

You can replace the tensioner without removing the head or even the timing belt. But you're way past that point

https://www.audiforums.com/forum/diy...g-belt-174109/

Awesome, thanks for that. I’ll probably change the other side while I’m at it just to be safe. I have the timing belt removed already and at tdc on cyl 3 the exhaust valves on cyl 1 are open. When I unbolt the cam caps will the cams try to spin around to a resting position? I guess if I can keep the cam lock bar on the whole time it shouldn’t be an issue.

[SoundEfx]

But do you know someone selling a kit........?

Awesome, thanks for that. I’ll probably change the other side while I’m at it just to be safe.

First and foremost, good luck with your repair.

Second point is the fact that the 'slippery slope' thinking has begun. Look at what you said.....lol

[projectvoltron]

Just keep the cam lock bar in position and you should be fine.

[mattg1.8]

Got the head off today and it doesn’t look good. Looks like I’ll need a piston and sleeve at the very least. Not sure what to do with it now, possibly a part out?