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Model specific boards => Golf mk2 => Topic started by: bigwes on 05 March 2009, 20:47

Title: 1990 8V engine noise????????????????
Post by: bigwes on 05 March 2009, 20:47
Hi all,

I have a 1990 Gti 8V and when the revs get above 3k its starts making what i can only describe as a "diesel" sounding noise all the way through, the engine has FSH and has had regular oil changes since i've owned it although it does have 150k miles on it.

My mate pointed the noise out i assumed they just sound like that??

Any ideas?

Cheers

Wez :nerd:
Title: Re: 1990 8V engine noise????????????????
Post by: 6foot6 on 05 March 2009, 21:05
bottom end bearings (con rod to crank)

If its sounding like a London Taxi then its them.

My 8v has a slight knocking sound (after it had sat for a year) Changed the oil to some thicker 15w/40 and its helped no end.

Get a long piece of metal pipe (or a big screw driver) put the end of pipe or screwdriver on the top of the rocer cover and put your ear to it and rev it (its like a stethacope)  then jack the car up and do the same thing with the pipe or screw driver on the sump.

Then get a mate to rev it and you should be able to make out its the bottom end or the top end.
Title: Re: 1990 8V engine noise????????????????
Post by: bigwes on 05 March 2009, 21:25
Cheers for the reply 6foot6

It sounds like the top end, it makes really good oil pressure??

Title: Re: 1990 8V engine noise????????????????
Post by: DarnPB on 05 March 2009, 21:30
Remove your oil filter and very carefully, cut it open, taking care not to contaminate it with too much iron filings. Remove the paper element and open it up. You are looking for silvery flakes, and if your bearings have disintegrated, the filter will be full of them. This is white metal, the material that big end bearings are made of.
If you find this metal in the filter, then you are in for an engine rebuild or change. This metal is not attracted by a magnet.
Title: Re: 1990 8V engine noise????????????????
Post by: nealey on 05 March 2009, 21:32
Check your cambelt tensioner isnt seizing up, i had the same problem with mine and it made a right racket
Title: Re: 1990 8V engine noise????????????????
Post by: bigwes on 05 March 2009, 21:51
Check your cambelt tensioner isnt seizing up, i had the same problem with mine and it made a right racket

This is a bit more optermistic!! i'll have to do some investigating tommorow when i have daylight and try eliminate things! :nerd:
Title: Re: 1990 8V engine noise????????????????
Post by: golf-gti-matt on 05 March 2009, 22:40
Even if it is big ends they may last a while yet! Have had engines knock for many miles before going boom!  :grin:
Title: Re: 1990 8V engine noise????????????????
Post by: Ben Lessani on 05 March 2009, 23:45
Remove your oil filter and very carefully, cut it open, taking care not to contaminate it with too much iron filings. Remove the paper element and open it up. You are looking for silvery flakes, and if your bearings have disintegrated, the filter will be full of them. This is white metal, the material that big end bearings are made of.
If you find this metal in the filter, then you are in for an engine rebuild or change. This metal is not attracted by a magnet.

Dropping the sump and checking deposits is a pretty good idea too.

And if you've got about 6 weeks spare, read this (http://www.golfgtiforum.co.uk/index.php?topic=104027.0)
Title: Re: 1990 8V engine noise????????????????
Post by: danny_p on 06 March 2009, 01:00
while you have the sump off can allways pop a bearing cap,    can redo the big end shells with just sump off if after a quick fix
Title: Re: 1990 8V engine noise????????????????
Post by: DarnPB on 06 March 2009, 08:33
Opening the filter is alot quicker, easier and less messy than removing the sump to obtain the same results.
Title: Re: 1990 8V engine noise????????????????
Post by: Wayne on 06 March 2009, 08:36
If it starts knocking as the revs rise it will be a bearing, I would check your oil pressure first and go from there.