Hi all,
Couldn't find this question posted before, so I'm gonna ask it now!
This Polo I bought (with only 55000 miles on 1993 grrr) just started the classic tartar sauce in the filler cap / white smoke out of exhaust so i just took off the cylinder head. Have had it checked and skimmed. What i was wondering is:
- are the head bolts that you see at E.G. GSF Parts, eurocarparts.com weaker or inferior to the ones you get from a VW dealer ?
They cost about 1/4 of the price which seems a ridiculous saving...
- what about the gaskets, especially the head one? Is it best to get the official VW one and not an aftermarket one ?
- I also had the timing belt changed about 7 weeks ago- so will it be worth changing that while i'm at it? Some people say that once they've been used you should never reuse them, however short the mileage.
- how likely is it that it will last for much longer, assuming i rebuild it properly?
Thanks a lot.
I'll buy you a beer (in theory)
NT
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I aasume you were loosing water as well as tartar sauce. I've used many sets of Europarts bolt sets and gaskets and never had a problem or a re-failure of a gasket. I do however re-tighten the head after 2K miles or so by backing after fitting the head to the specified angular method I mark the bolt position back it off and use a torgue wrench and establish the actual torge that the final angle required. Then later at the 2K miles mark crack all the bolts back by 10 degrees and then torque then down to the acquired figure. you would be surprised how uneven they head bolts become the looser ones are normally in the same place on the same car I guess due to thermal effect and head gasket settling. The I buy a used car this one of the first thing I do is check the head bolts. Regards Peter
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Yep, losing about 2 pints every 10 miles :(
Sounds like an angular torque gauge and a physics textbook would be a worthy investment..
Thanks.
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I stand to be corrected but if they are stretch bolts which you tighten up using an angular setting procedure, they should NOT be slackened off and retightened. Even using the procedure outlined. Once they have been stretched I believe they loos their 'calibration'.
Interesting that bolts appear to slacken off by different amounts though!
pmh (was peter)
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The haynes just says to tighten them in the right order, to the specified torque. Also that VW say you don't need to replace them if there has been no stretching, but haynes recommend that you do anyway whenever disturbing them.
I have the kind of wrench where you set the torque, then it clicks when you reach that amount. Not sure how this angular talk fits in with this - isn't torque torque?
cheers
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No not really the Torque is established during the normal angular tighening of a new bolt and I have tested the re-torque against a new and on original bolt to fined they are very close to the finshed value. The Torque does not exceed the the dynamic stretch of the bolt so its elestic limit has not been breeched. As I mentioned in a previous topic Pug agents remove the bolts on a 106 and probably others to remove and inspect the cam then refit the bolts and angular torque them down. However if you did that with a Polo engine you would fracture the gasket seal as the head is not on dowels and could move. Personally I would not ever remove all the bolts without replacing the head gasket. If you have had experience of head type problems and long term protection of an engine you would have come across loose head bolts. An example was a Golf engine and some bolts were as low as 55 ftlbs and other were up at 75 and when angular re-tighening of all of the bolts ended in a figure approaching 85 on re-test. More interesting is checking several other golf heads it is the mostly the same bolts that are loose. I covered this in a reply to someone asking about what causes head gaskets to blow. On a Polo it is often the rear left corner the goes and you can almost guarantee that the corner bolt and bolts 4,5,and 6 are quite loose. due to the friction bond under the head of the bolt you can not just test then with a torque wrench but have to be cracked off ( undone )by 10 degrees first, thats when you realise that some are quite loose. Even checking the bolts say at 70 ft lbs and not cracking them off you will fine loose bolts but this method is unreliable. These torque figures are not a guide for you guys to use as thay are engine dependent and of course material and bold dependent i.e. ali blocks. Thats why I establish the figure by angular tighening then check all other bolts. New gasket, new bolts and washers, some wachers a sided and should be dome up and burr free. Regards Peter
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NT your Polo bolts are to be angularly tightened and new bolts and washers are preferable but many mechs reuse the bolts and washers. A few might measure the bolts for signs of necking,i.e. over stretched, and I have seen reference the re-using the bolts but measure their length and replacing those that are out of spec. Your Polo has no dowels to locate the head so care has to be taken without the alignment tool. if you get is grossly wrong the cam belt can ride off centre on the cam pulley. If you want to be sure clean two bolts then wrap elctricians tape neatly building up the diameter in a couple of places so you can insert them in the corners and centralise the head. Put in the other bolts and nip them up and remove the taped bolts to remove the tape then re insert. Now follow the book to the first stage. but pu the cam belt back on now and check the markings. Then turn the engine ever, no plugs, 10 times on the pulley bolt to ensure the cam belt is running true. Then complete all the angular tighening and retension the cam belt it will ahve loosened as the head pulled down. Regards Peter
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Hi,
My Polo (like many others) had the head gasket replaced in 1998 (with 56539 miles). As this operation was not done at a VW dealer, I would assume that the parts used are not genuine, but I cant say for sure whether this is true. As the car has now done in excess of 103000 miles without any other attention in this area, I can say that:
A) Aftermarket gaskets (if of a good quality) would probably be just as good as a VW one, but a VAG specialist may supply a part which is of OEM manufacture but without the VW dealer pricing.
B) As the bolts were not changed on mine, if yours don?t show signs of damage or stretching then you might be able to re-use them. (I?m no mechanic however)
C) Regarding the belt, well as they don?t cost much, I would change it anyway for added piece of mind
D) I would say it would last for a while yet, as long as it hasn't been used for door to door runs too often and it has been serviced properly (and you continue to do so)
Lastly, I read somewhere that a lot of 1991-1994 Polos had their head gaskets changed as the mating surfaces were not as good as they could have been which lead to a few premature failures at similar mileages. (seemingly between 45k and 60k)
My info is not as good as Peter D's, but I though I would mention it anyway.
Good luck with it all, and let us know how you get on
Roberson
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Right, i have the head back on but have got a really annoying problem- the timing belt just won't fit! I've tried every possible kind of jemmying to get it back on, but it just won't {I'm a silly boy for trying to trick the swear filter into letting me post a naughty word} fit on.
Also, I did have loads of trouble getting the alternator pulley off the crankshaft, as i've found other people saying- the result being i had to smack the hell out of it dislodge it from the crank, like really beat it for about 30 mins non stop! Is it possible i bent the crank :( ?
It's the crank bolt that stops you easily sliding the pulley off....
any help appreciated muchly.
thanks
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mmmmm, I would say its quite difficult to bend the crankshaft so much that the timing belt wont fit, but may be wrong.
I take it that this is not the belt you had fitted initially and is an entirely new one. If so, the only thing I can think of is that it is the wrong one. Looking at a Euro car parts brochure, there are two belts. One for 1982-1990 and another for 91-. Looking at another Volkswagen parts website, there is only one part number. (?) What could be the problem is that the two belts have different amounts of teeth meaning one will be smaller.
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It sounds like you have not undone the water pump which is how this engine adjusts the belt tension. The water pump pully is asymetric in the housing and the 3 bolt holes are slotted to allow rotation of the pump. Do yourself a favour and and go buty a new "o" ring seal for the pump. If you have done 100,000 miles buy a new pump and seal, fit and tension belt properly. Regards Peter
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It's a new belt from a car parts shop, guess i could try and find the old one and double check it's the right one...
have tried removing the waterpump & bolts, then fitting the belt, then tried to bolt the pump back on, but it won't straighten up properly, it keeps rubbing the timing belt cover. It really seems like either the belt is too short or the crank has bent downwards.
Will experiment...
Thanks
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Try taking the belt back.Armed with chassis no. otherwise engine no. If the belt is wrong it will show up..on parts list..Though often find wrong part in wrong box..
--
Steve
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Put old belt against new one. Connect together with clothes peg or similar. Double check you have the right one before taking it back. Check same length, same number of teeth and same profile (round or square profile)
Similar program with the Peugeot engines when they changed the tensioner.
I got the correct one (113 teeth, I think)eventually
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Right, finally all back together but with mixed fortunes!
I started it up ok, it ticks over ok, but the timing belt is slightly to the left of the cam pully. Poo. Could this be that the timing belt is too tight ? Or have i muffed up something ?
I tried shoving it back towards the centre but straight away it slips back again.
Let it tick over only for about 30 secs, as was worried it might slip off altogether.
Any help appreciated...
thanks
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I did explain to you quite clearly about the head alignment before and turning it over 10 times to see where the cam belt runs.. That said, when you say to the left is all the belt on the pulley i.e. not trying to lip over the side. Regards Peter
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Yes, you are totally right but I just followed the haynes as my back was aching too much...it's off to the left as you look at it, I think it was slightly over but I'll have another look tonight.
But i still don't see how the head can be so side-aligned that this could happen. Why don't the head bolts stop it drifting ?
If I keep it as is, do you reckon theres any chance that the belt could come off? I guess also that if it is that the head isn't totally aligned, there will be some head gasket leakage.
I did also fit a new water pump if that could be related...
thanks alot.
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Ran it for about 8 minutes under no load, and it seems to be right on the edge ie with no overhang. Guess if it was going to get worse, it would have done?
Given the amount of torque needed to actually start the engine, I'd have thought that would be the most risky part.
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As long as it is not over the edge and the belt tension is OK then it will be fine. The minor head mis-alignment will not cause a problem with the gasket. Regards Peter
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Thanks Peter.
One other thing thats happened is the exhaust manifold heat shield was so corroded i had to hack the nuts and a couple of the studs off in order to remove it...so now i have no way of attaching the heat shield (other than glue).
How useful is it ? I guess the hot air pipe that goes from here into the air filter is needed for the carb. It is also ticking over too high after warming up... could be related ?
Excuse my numptiness!
thanks
NT
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