Valve stem seals gone after head gasket repair

[Catherine41]

Hi, I just wondered if anyone can give me some advice regarding what I suspect to be a problem with the valve stem seals? 

 

My timing belt slipped recently and the garage said they had to replace the head gasket also when doing the timing belt.  Since getting the car back, it is struggling on acceleration, jerking as if about to stall. No smoke from exhaust that I've noticed but it's burning through oil (at least 5 litres in the last few months).  Engine light has come on a few times and it was showing a code for the MAP sensor which I have recently replaced but still having the same issue. 

 

So my question first of all is, would replacing the head gasket have affected the stem seals? (As I never had this issue prior to having the head gasket and timing done) and if so, what are the chances of the garage rectifying this, e.g. is it a no brainier or would they have a case to say one is nothing to do with the other? 

 

The other question is, could the code for the MAP sensor be related to the stem seals as I'm guessing this will affect the levels of combustion gases/air coming through the sensor? If anything it is worse since putting on the new sensor, maybe because it's more accurate being brand new? 

 

I may be totally on the wrong lines as this isn't my field, I'm a nurse and need the car for work in the community so would really appreciate any advice! 

 

It's a skoda fabia, 2010 and has done roughly 95000 miles 

Thank you! 

Catherine 

[xman]

What engine?

 

Likely bent the valves when your timing belt "slipped" and the pistons made contact with the valves. Did they check the head, valves etc thoroughly when they removed it and changed the head gasket?

 

Need to perform wet and dry compression tests to determine the health of the head/valves/pistons.

 

 

[Catherine41]

Thanks xman, yes they had to replace a couple of the pistons which had bent when the belt went so sounds like they checked everything, or at least thought they did, I'm guessing you wouldnt necessarily know the seals had gone just by visual inspection, or would you have expected them to do a compression test as a matter of course when doing the head gasket? 

 

 

[xman]

You still haven't said what engine you have. Petrol/diesel, capacity, engine code if known.

 

If the problems started immediately after the rebuild then its obvious they didn't do a good job.

 

Damaged pistons, bent conrods, bent valves, seat/stem damage, cylinder wall damage, even crankshaft all possible.  Should all have been checked and a compression test done after a rebuild.

 

Who did the work, is there any warranty?

 

 

[Catherine41]

Sorry its a petrol 1.2l, I wouldn't know where to find the engine code? 

 

It was a local garage that did the work so I'll see if they will cover the repair costs, or at least partial repair costs now I know they should have checked it at them time, thanks so much that's been very helpful! 😊

[xman]

1.2 (either the 4 cylinder tsi or 3 cylinder htp) engine is a camchain and not a cambelt engine. I imagine there was lots of damage when the chain jumped or more likely left the sprocket completely.

 

The head damage could have be extensive, bent valves, damaged seats, stem seals,  hydraulic tappets, camshaft followers, carrier bearings.

 

There's usually a loud rattle (on start up) before a chain goes, a warning that its slack, but that's in the past now.

 

First should be a compression test.

 

[Catherine41]

Thank you so much for your help, I suspect it did leave the sprocket completely and the machanic that worked on it did say the damage was extensive, I actually took it back to him after the work was done as there was oil coming up through one of the ignition coils which then needed replacing, Id actually forgotten as it was a few months back now but I recall he actually mentioned at the time that there must be a problem with one of the seals and sent a video of lots of smoke coming from the exhaust (which he said was because it had been run idle for around 20 minutes) He suggested it would be a further £300+ to repair which I couldn't afford at the time and it seemed drivable but given what you have said it sounds like he would/should have known it was related to the timing work he had done and offered to rectify it 🤔

[J.R.]

Unlikely that the valve stem seals will have been damaged, if they were it should have been picked up, they could be claiming that as it would invite less critical questioning than the (to me) more likely option of piston/bore damage.

 

I would take it somewhere else for a compression test and second opinion before going any further down the road with the current garage, I hope I am wrong and at least this way their diagnosis will be validated and you can have confidence in them.

 

20 minutes ago, Catherine41 said:

he actually mentioned at the time that there must be a problem with one of the seals and sent a video of lots of smoke coming from the exhaust (which he said was because it had been run idle for around 20 minutes)

 

That sounds plausible, its simply that I don't take as gospel anything a garage says without doing some analysis, the price quoted sounds correct if the oil consumption is from the valve stem seals. A compression test will rule out piston/bore damage and the other garage will know how to test for stem seal oil consumption.

 

I wonder if they forgot to fit them? 💡

[Catherine41]

Oh maybe they did forget to fit them! I guess if I took ot to another garage for a compression test, they would be able to advise if it's something I should take up with the original garage, I'll have to try and find a reputable garage, something that seems more and more elusive! 

 

Any idea how much a compression test would cost? 

[Paws4Thot]

14 minutes ago, Catherine41 said:

Oh maybe they did forget to fit them! I guess if I took ot to another garage for a compression test, they would be able to advise if it's something I should take up with the original garage, I'll have to try and find a reputable garage, something that seems more and more elusive! 

 

Any idea how much a compression test would cost? 

A compression test would be irrelevant if the valve stem oil seals need replaced. Compression occurs with the valves on the cylinder which is compressing closed and the oil seals are on the top of the head, not exposed to the compression. Does the engine give blue smoke on overrun and/or first application of throttle?

I'm trying to figure out whether further internal damage or oil seals are more likely from first principles diagnostics.

[Catherine41]

I've never noticed any smoke whatsoever, the only time I've ever seen smoke was when the garage sent a video of this from the garage shortly after I'd dropped the car off, I'm assuming the smoke would more likely indicate internal damage? 

[J.R.]

Not at all irrelevant, the compression test is to check for compression losses or to confirm that all is well with the most likely cause of oil consumption, piston & bore wear or damage, if it gives good results and there are no obvious significant oil leaks then the valve stem seals or absence thereof are the cause.

 

It should not cost much as its a 5 or 10 minute job, I wont hazard a guess at price as I have not liven in the UK for 20 years and never used garages for repairs even before then.

[Catherine41]

OK thanks that makes sense👍 if I'm understanding correctly, either way, it sounds like something the original garage should have checked/repaired when they did the timing and head gasket? 

[xman]

What caught my attention was

4 hours ago, Catherine41 said:

Since getting the car back, it is struggling on acceleration, jerking as if about to stall.

 

These symptoms reminded me of my old (76) Polo that had a burnt exhaust valve seat and losing compression, so I'm thinking if there is a

bent valve stem, damage to a valve seat or something  preventing proper valve closure that might explain the above symptoms. 

 

Wet v dry compression test would show valve v ring/bore damage

 

[Catherine41]

OK thank you, I'll try to find a garage that can do the compression test as you have suggested 👍

[Jocko]

I had a SAAB 99 with dodgy valve stem seals and if you descended a hill on a trailing throttle and then accelerated at the bottom, there was a plume of smoke from the exhaust, clearly visible in the rearview mirror.

[Catherine41]

Thanks, Yes I have now noticed some smoke today, not enough to notice though unless I'm looking for it 

[Catherine41]

Thanks everyone for all your advice, I have contacted another garage who specialise in engine rebuilds/repairs and they have advised taht a compression test won't help so aren't prep elated to do this and advised I go back to the original garage as it's almost certainly something they have/haven't done. So I've contacted the original garage and he was very rude (it's upset me quite a bit to be honest) he said as I never took it there to have the stem seals done then he wouldn't have done this.  I have said that teh advice I've had is that this should have been done as part of the rebuild and compression checks so he has agreed to lool at it in 3 weeks however I'm due to move out of the area before them which he is aware of so I'm totally at a loss, I can't force him to look at it sooner and the other garage said it would cost 1.5k to strip and rebuild everything to find the problem 

[xman]

There must be plenty of garages  who do engine repairs/rebuilds around Manchester, try googling "Manchester German car specialist engine rebuild" and give them all a ring.

[Catherine41]

Thanks xman, can I ask, if I hold off and wait for the original garage to look at it, and assuming it is the valve seals, how much can I expect to have to pay for this repair? My assumption is that I shouldn't be charged for the labour as this is something that should have been done as part of the rebuild initially and therefore would think parts and maybe an hour labour is very fair? 

[xman]

Unfortunately it's going to be a lot more than an hour's labour. They will need to remove the cylinder head and strip it all down.

Its going to be expensive.

 

That's assuming the problem is valve stem seals, could be much more damage that the garage didn't fix properly

 

Might be cheaper to replace the engine.

 

You need to shop around.

Edited 27 February by xman

[Catherine41]

OK thanks for the heads up, I'd expected since this was something that the garage has missed/failed to check when they did the timing belt and head gasket, that the remedial work should be covered by them, I. E. If they had done a thorough job in the first place when the engine was already stripped down, it would have only been the additional cost of the seals had they done it at the time, however following my last conversation with them it doesn't sound like something they are prepared to take responsibility for and given what you have said, it's looking like I'll probably have to try and sell it for spares/repairs and cut my losses 😔

[Warrior193]

Good afternoon @Catherine41 - from your description of the issue and the subsequent, reaction from the garage that carried out the work, putting aside the oil burning issue for the moment - I'm wondering if they made an error in the valve timing when replacing the chain. If you do take it to another (qualified/rated) mechanic, I suggest the timing be checked first - at least that way, if the timing is incorrect, you have the original garage on the hook for the repairs because of their mistake. 

[Catherine41]

OK thank you for your advice, I'll see if I can find a garage to check the timing 👌 do you know what the cost for this check would be? 

[thomasaspin]

A cause of smoking after a belt snap / slip can be fitting new oil control rings / pistons rings into an old bore without honing the bore also if the pistons did slap the valves then it can scrape the bores causing ways for oil to get into the combustion chamber , it would of been cheaper to drop a second hand 1.2L engine into your car than to pay for a rebuild sounds like they have ripped you off and I would be making a warranty complaint