CAM belt failure. What damage do you think has been done?

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jp1

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What's the general concensus of opinion in the amount of damage that may have been done to my engine (1.8T) due to cam belt failure?

Small amount of belt noise from the engine, originally I thought it was the aux belt, either slipping or the belt tensioner vibrating. In the end it turns out to be the water pump seizing.

Drive out of work in the evening and 400 m down the road the noise becomes more severe and I realise it's a problem. Limp back to the office, ( so I drive the car 400 m with the problem) and switch off. Now at this point the belt has not failed, the engine is running normally, albeit with a very disturbing belt/squealing noise. Lift the bonnet and I can see that coolant has been sprayed around the bay, with rubber shards in the water.

RAC called out to tow me home, guys asks me to start the engine. It starts normally with more belt/squealing noise. Shut down after 20 seconds.

Towed home and because of the layout of my drive I have to start her up to get on the drive. Turn the key, she cranks but does not start, try again still does not start. In total cranked for around 5~8 seconds.

Reading around on similar problems, it's almost certain that the water pump has seized and the 400 m driving (at very low speed) and subsequent start up has shredded the teeth off the cam belt, but just about maintained some sort of structural integrity to keep the timing correct.

Trying to crank the engine over after being towed has caused the belt to slip or fail completely.

So what is the likely damage to values from trying to start but failing???

It will be looked at by an Audi specialist for a water pump and cam belt change in a few days, when I will know info, but before then any ideas?

Thanks
 
Bent valves and damaged lifters. You need to pull the head...
 
I hope not..

Car wasn't being driven with a snapped belt. It fired up and idled ok.

The car has been cranked only and failed to start. I had a quick look at the belt this morning, by prizing the cover back a bit. Belt still in place and seems secure around the top sprocket, certainly still has teeth on the belt, but they have been trashed obvioulsy. Couldn't get a real look at the lower part of the belt and I am not sure if the tension was a little on the loose side.

What I was really posting for was a consensus on whether in this situation the engine is always screwed, or that there is a good possibility that the belt has just slipped a few teeth and hence now no longer starts.

I appreciate that in most situations driving the car when the belt goes your going to drop a few values and bend them, not sure if this is the same situation.
 
There's always a chance that you've not damaged anything, but realistically you've only got to be a tooth out for things to meet and bend. Fingers crossed you'll be lucky.
 
even at cranking spped valve will have touched and she will be a gonner.

If the timing was correct, it would have started.

Used head is cheapest/easiest as it's a direct swap, failing that new valves and/or guides as a min
 
Ok, thanks for the replies.

I''ll see what my Audi specialist says when he has a look at it and post back.

On another note how difficult would it be to replace the head myself with a reconditioned unit. Am I correct in thinking a recon head, (including valves cams etc) is around £350. The car is a 2003 1.8T 190 SE

Once took the head off and stripped it down on my 1.3 Chevette!!! (many years ago) but these days I don't really work on cars and my tool set is a bit depleted.

But if it's a case of scrapping the car (realistic pre accident value £2800??) then I might have a go at it myself as I have nothing to lose. but not sure of what specialist tools are required and whether it's a real pig of job.
 
have the head recon with valbes etc
your gona struggle to get a second hand head
and you would want it in the shop to check even if you found 1
you dont need to be driveing to cause damage
as above if timeing was correct it would start a tooth or 2 out and things bend
good luck
 
Update..

The cam belt was out by about 15-20 teeth, some of them pretty badly chewed.

New water, pump, belt and tensioner and fired up first time.

400 miles now driven, no noticeable oil consumption, power loss or any unusual noise. So looks like I got away with it!! Someone must like me.
 
Great news matey, as you say, thankfully someone must be looking out for you. Glad it's all sorted.
 
You're a lucky ****** alright, mine only skipped 4 teeth and it was goodbye to the engine!
 
jp1 - can you start a lottery syndicate for the big 166 tonight?!?! Sounds like you got very lucky there!
 
Glad to hear the engine is ok, would have been a mare of a job otherwise. I can only assume the camshaft stayed still in a lucky place i.e with the valves all in the half open / closed position (if there is such a position they can all be in!) and while cranking the engine the pistons were flying up and down and missing all the valves. Did you replace the pump with a metal impellored one?
 
Yes mate, count yourself lucky, you have at least 2 valves bent and when they drop they'll take the engine with, dont worry about the brass guides ! Trust me, i've seen it before a couple of times, usually it takes 5-10 k for the valve to break at the stem/cotter end and drop inside...Not good for the engine at all...
 
Very , very , very lucky you are :yes:, I would have put money on it that it would have taken at least 1 valve out, Ive never been successful when customers have asked me to fit a new timing belt when its gone.
 
adamss24 said:
Yes mate, count yourself lucky, you have at least 2 valves bent and when they drop they'll take the engine with, dont worry about the brass guides ! Trust me, i've seen it before a couple of times, usually it takes 5-10 k for the valve to break at the stem/cotter end and drop inside...Not good for the engine at all...
Click to expand...


Just an update to this thread.

Now 10k miles added and the engine sounds as good as new. Still plenty of power @140k miles
 
Never seen something like this, the engine is an interference and valves will come into contact with pistons when the cambelt breaks. I have rebuilt a 1.8 NA a few years ago and every inlet valve was bent- timing belt lost a few teeths. Fortunately the lifters were ok and it just required new valves... You're lucky but i still don't believe it !
 
Lucky indeed I'd say!! I've just had my cam belt done last week, and I must admit I sleep a little easier now. I didn't dare do it myself as a few on here have.
 
Glad to hear its still going strong!
My waterpump siezed on the 2.5 a few months back - luckilly the pump is driven from the flat side of the belt on the 2.5 and saw the smoke at a set of lights so was able to shut it off and have it towed home.
It would have been a different story if I was on the motorway - I wouldnt have seen any smoke!
 
Hello can any one help me i have a audi a4 2.5 v6 tdi convertable i had garage do my cambelt and service had a full kit put on i had it back a month and my cam belt has gone slack after stripping it found a tentioner had sheered off any idea if i will be lucky if put another new belt kit on that it wont have done any damage to my engine ?
 
I pulled off a roundabout in 1st and mine failed and bent everything! Very lucky!!
 
antony 89.
Why didn't the garage advise you the tensioner should be replaced? If it was that worn it would have been obvious to them it was u/s.
I'd take it back to them and say sort it!
 
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The 2.5 is an interference engine. My belt snapped coming off a roundabout. Cost me £2500 just for the new valves, gaskets and belts etc. The car was only 3.5 years old at the time!

So basically, you won't get away with just replacing a belt and tensioner.
 
I had evrything done bakpak even water pump.cost me 800 to have done and oil change
 
Thats a pic of it
 

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That engine
 

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Well how do the garage explain the failure? It is clearly down to them mate. If this happened to me after one month I would hold them 100% responsible, unless of course you popped to the moon and back.
 
They said its me cam shafts nout to do with cam belt that they done rang trade and standards they wanted 700 for a independant inspection
 
What a nightmare mate!
It would be good to hear adamss24 opinion on this, he clearly knows these engines inside out.
 
Not happy so dint no weather to get another full cambelt kit and re do it and see if i have got lucky or not and then if not look for new engine
 
That has almost certainly spelled disaster for that 2.5.
The tensioner will (should) have been replaced as part of the cambelt kit - it looks new anyway.
I would say the tensioner pulley was obviously to blame for this - either workmanship or a defective part. Can you find who the cambelt kit was made by and if they offer warranty on parts/damage?
 
Im gonna see of i can find out so you think it gonna be alot to get put right ?
 
I would imagine there would have been some valve to piston contact - I guess the only way to tell is to remove the cylinder heads and inspect.
 
In your case most likely they over-tightened the bolt holding the tensioner which is known to strip threads in the alloy housing. The cams can also to blame- later B** engines have hollow cams which are notorious from snapping the rings on them ESPECIALLY when cambelt breaks ! I would be very, very surprised if the heads and cams are not damaged ! Each cam is big money from TPS and you need 4 as the replacements are solid... I think your best option is to look for a good 2nd hand engine or sell as it is spares or repair... If you want a good engine, i have a BDG 163 Bhp which i have rebuilt not long ago for one of my projects which i don't think i will finish due to owning too many cars !
 
How much you after for the engine ? Would it fit straight into mine
 
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