Almost lost the engine in the A6 yesterday

Status
Not open for further replies.
T

threeputtpar

Joined
Aug 4, 2011
Messages
2,128
Location
Appleton, WI
Over the weekend, I pulled the timing belt and one roller and tensioner to fix up a coolant leak at the thermostat housing (stupid Audi engineers). I've been this far in the engine several times, so I'm confident in my work.

Driving home from the office yesterday, I pulled off the highway and at the top of the off ramp it sounds like there's a large can of marbles under the hood. At this point, I'm only about a mile from home so I nurse it back to the garage and park it for the night. It was running normally, with no misfires detected. Not even a CEL, but it did not sound good. I'm thinking (hoping) that the serpentine belt tensioner has given up on life and is no longer holding tension, resulting in the noise I'm hearing.

I pulled the viscous fan and clutch and the serp belt and fired it up to see if the noise was gone. Nope, it's still just as loud and unnerving. Time to dig deeper.

Here is what I found:



OK, that's not a good start!



Ummm, that's melted plastic on the tensioning lever.



Something's definitely missing there.

I didn't get a pic of it, but the roller that places tension on the belt was no longer attached to the engine block and one of the washers was MIA. I'm certain that I tightened it when I put it back together after the coolant repair. With the new parts I'm putting back in, I will certainly be using a liberal amount of threadlock this time. I don't know how the thing still ran for that last mile, as the belt was very loose on the pass side camshaft sprocket and that bank was about 15 degrees out of time with the other side and crank.

And yes, I've purchased a couple of lottery tickets.
 
I've had improperly torqued bolts and nuts come off and bite me in the [censored] too. Some hard lessons learned!
 
Originally Posted By: RISUPERCREWMAN
Your a lucky Dog! That is why I'm done buying cars with timing belts!


+1 no more timing belts for me. If one breaks on you the best you can hope for is to walk home. The worst is the need to carry a new engine back to the car.
 
Ouch!

really lucky that wasn't an expensive issue.

Good luck with the repairs. I'm hoping there aren't more surprises for you...
 
I had an identical thing happen last year - with an Acua, not my Audi. Below is a pic of the belt cover with a round hole bored in it where the pulley worked free and chewed through.

When I tore it all down what I suspect really caused it was the tensioner. So check that on your A6, too, before re-assembling.

The belt had been done by an Acura dealer on schedule, and was not due for change. They DID NOT change the tensioner when they did the belt change. What I found was a water pump with a manufacture date in accordance with the change date, and a tensioner with a manufacture date several years earlier, the month prior to the vehicle build date, and much more worn than other components. The tensioner was re-used and was shot, and what I think happened was it allowed the belt to slap and loosen the pulley. While it LOOKED like it was the pulley's fault superficially, it was the tensioner.

Check your tensioner throughly before re-assembling everything. It may be just your pulley, but double check.

This is the 2nd time I've had a belt fail; both times were dealership jobs. This is why I now do all my own belt changes - they get done properly and don't fail.

IMG_20140124_113540.jpg
 
vtbS3010005.jpg

vtbS3010006.jpg


This was my doing on a volvo 940. Had to pull the top half of the timing belt cover to get at one water pump bolt-- dropped something in the lower half of the timing belt and it was banging around the crank pulley, wrecking stuff when I restarted.

Good news was it happened at home.
laugh.gif
 
Originally Posted By: Oro_O
Check your tensioner throughly before re-assembling everything. It may be just your pulley, but double check.

This is the 2nd time I've had a belt fail; both times were dealership jobs. This is why I now do all my own belt changes - they get done properly and don't fail.


The hydraulic tensioner was the first part that I tested to make sure it wasn't toast. It was fully extended, but there's no evidence that it lost any of its fluid. Slowly compressed it in the bench vise and pinned it and it will go back in with new roller and lever. The water pump bearing is whisper quiet and smooth, so that will remain along with the new thermostat and o-ring.

I think I've had the opposite experience as you have, both TB jobs were performed by me and my wife is now crowing at me that I should just let the dealer do this one and be done with it.
21.gif
 
Defiantly lucky. Luckily even tho the KIA has a timing belt its a non-interference engine.

I learned from experience that even if the tensioner seems good, i always change it. If i have it removed and spent the time, mine as well cover myself.
 
Originally Posted By: JBinTX30
Defiantly lucky. Luckily even tho the KIA has a timing belt its a non-interference engine.

I learned from experience that even if the tensioner seems good, i always change it. If i have it removed and spent the time, mine as well cover myself.


A non-interference engine means you still walk home when the timing belt breaks.
 
True you still walk, but your wallet takes less of a hit and you can keep your engine. I had one brake trying to start the Isuzu the water pump seized, but that was a non interference engine as well. That was the day i bought it but it ran fantastic after it was replaced.
 
Well, this straight forward repair has taken a turn sideways. This is where the tensioning roller used to be attached to the engine:



Yes, that's the end of the fastener broken off in the block! There just isn't enough protruding to be able to grab it with a locking pliers, so I'll have to get an easy out in there with a right angle drill. Either that or remove the entire front radiator support so I can use my normal cordless drill. Luckily, it's a smaller diameter fastener that didn't take all that much torque to set so I hope that it will break loose easily.

Here's a shot of the room I have to work with. The busted bolt is in the exact middle of the picture:



I'm all ears if anyone has a better idea than a pilot hole and using a screw extractor on a right angle drill attachment.

And I kindly ask that we don't turn this into an all out debate on belt vs. chain. At this point, that argument means nothing to me. Thanks.
 
Can you notch it with a dremel and try a flat head screwdriver? Blast it with PB or equivalent, use a hair dryer to warm up the housing around the screw, and try to unscrew it.
 
Dang man that sucks! Glad you made it home alright without losing the engine. I also suggest what L_Sludger mentioned about using a dremel to cut a notch in the bolt and backing it out with a screwdriver. Heat around the bolt is also very helpful.
 
Originally Posted By: jeepman3071
Dang man that sucks! Glad you made it home alright without losing the engine. I also suggest what L_Sludger mentioned about using a dremel to cut a notch in the bolt and backing it out with a screwdriver. Heat around the bolt is also very helpful.


That was the thought I had this morning on the drive into work. My BIL has a Dremel and I have a cordless screw gun that would fit down in there. I'm hoping I don't have to resort to a propane torch because the front of the engine is covered with oil. My wife wouldn't approve of me starting the garage on fire, but I wouldn't be too broken up at this point if the car were to mysteriously go up in flames out on the road.
whistle.gif


Audi sure didn't have the ability to keep the oil in their engines!
 
Last edited:
Was it a Torque to Yield bolt? Did you replace it? If not you are your own worst enemy in that regard.

My research shows it was...

Also the bolt is so cheap why wouldn't you replace it? See this is what happens when you cut corners. The fastener has a certain yield once it stretches when trq down. It only does that once and if you reuse it this is what you find the failure point. Consider yourself lucky your are not getting the heads rebuilt.

Right angle drill and an easy out is the simplest and easiest. Go slow and use oil when drilling.

Also I agree with your wife lol
 
Last edited:
Status
Not open for further replies.

Similar threads

SwampSurvivor
Guides and Chains in my 01 Grand Marquis ... I told ya so
2
Replies
23
Views
2K
SwampSurvivor
T
What causes windshield wipers not to pivot / alternate ?
Replies
3
Views
389
Kantaro
Fabulous50s
Toyota 1AR-FE (2.7L) intake cam phaser
Replies
5
Views
1K
Delta
OM605
Driving without a fan
2
Replies
32
Views
2K
antonmnster
3
Wife's 2013 Hyundai seized up today 94k miles
6 7 8
Replies
158
Views
8K
350Rocket
Back
Top