As you may have read elsewhere, I have just replaced the head gasket on my '93 1.05 Polo. (Injection)
Its now idling at 1000-1100 rpm (about 300rpm too fast). What could it be?
As far as I?m aware, all connections/pipes are installed securely, so could it be either valve or ignition timing?
The car is running better than it ever has before, with a smoother idle and better performance (just in case that helps)
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Is the engine pinking at all? The timing would not be affected unless the cambelt was put on a tooth out (or more) but I think you would notice it. The valves are hydraulic so nothing to adjust in themselves.
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No, don't think so. But then again, I?ve never experienced it before. We had some trouble with the camshaft pulley upon re-assembly. The woodruff key seemed to be worn (?!, I have pictures if it would help) to the extent that it was possible to rotate it to the point where there was 2 teeth difference. Having made a note of the timing when disassembling, we are pretty sure the timing was as it was prior.
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Bit of an update:
The idling issue seems to have solved itself! But this wasn't without problems elsewhere.
I had a look this morning to see if the throttle cable was correctly installed, as my dad had a idea that this could be the problem (being too tight and opening the throttle slightly). Took everything off to get at it, and it seemed ok. Then I thought I?d give it a run, just to make sure its still doing it, as I?ve booked into the garage on Tuesday for an oil, oil filter and coolant change. Not only that, but I?ve also asked them to have a look at the idling problem.
Started it, and what a racket. CLACK CLACK CLACK of an empty hydro tappet! Oh dear. I drove away thinking it might get less, but it didn?t, so returned home after about 60 seconds of starting. Now feeling rather sick with worry that something was terminally wrong, I decided to whip off the cam cover, expecting to see scored lobes etc. Peering with one eye open, everything seemed ok, if not as oil-drenched as they should be, but no scoring. Phew. But what about the noise?
The only thing I could think of was crud blocking the oil filter, preventing full flow. After a soothing cuppa, I went (on the bus) and bought an oil filter (£5.99 for a Champion, huff, tut. Would much prefer a Mann Hummel). By the time I got home, my dad had arrived. Telling him about it, we went for another look. Started it: CLACK CLACK CLACK?. Just as we were about to turn it off, it all went silent, as the clacking disappeared!!!?? So we kept it running, and then went for a brief run for about 10 minutes on the dual carriage way. The noise never came back. Now, all we can think of was some debris blocking the oil feed for one of the tappets.
That oil and filter change can?t come soon enough?.
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It possible the hydraulic tappets need replacing, not unusual on these engines when they turn 100K. When I replacd the head gasket on mine I put a new set of tappets in at the same time since one was making a racket from time to time.
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Thanks for getting back Xileno.
I'm pretty sure its only one of the tappets running completely empty. The longer the car is left the longer the tappet is audible when restarting. If left for a few hours, it'll clack for about 10 seconds. If left for days, it'll clack on for a minute or so. Still, a very painful sound. What is confusing me (easily done!) is why the noise stops all of a sudden and not a gradual fade?
An oil and filter change may help but not cure the problem, is that right?
I'm going to ask the garage for their opinion on Tuesday, but in the likely event of the noise continuing, I?m going to ask for a quote for repair. Am I also right in thinking that it's a relatively straightforward job on this unit? Also, if its only one tappet that?s shot, can you replace just one and in any case, how long do you think it would take an experienced garage to do (then I can work out the cost).
Sorry for all the questions
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