new golf trouble fast idle and smoking!!!

Hi guys and girls, i really hope someone can help me out here…
Bought a '83 1.8 Gti Mars Red looks like a little beauty but

The engine ticks over at 1500 at first and then dropps down to 800-900 after a couple of minutes.
Then when the engine gets hot the idle goes up to 2000rpm.
Also there is white smoke coming out of the exhaust and it leaves a large trail of it under acceleration. I think its burning oil.
Ive had a compression test done at it seemed fine.
Ive changed all the fluids, filters, leads and plugs.
Anyone had this problem?

Steve

just been doing some searching and found a thread with a similar problem with the fast idle.
Can anyone explain or have a picture of where the idle screw is as i think its this. Its gone up to 2200rpm tickover this morning! sounds terrible and is still smoking under load
Cheers

Steve

Sounds like your problem is more than just Idle screw adjustment?!?
For reference though, it is on the back of the throttle body, 7 or 8mm spanner I think…

I once test drove a MK1 cab that idles at 3000rpm once warmed up!  The vapour trail could be a blocked oil breather filter - these are fairly simple to change.  Might be worth dropping the car into a Bosch fuel system specialist to have a look at the idle as you may end up changing all kinds and spending hours on it for the sake of a few quid.

Steve
how do i unblock the oil breather filter? where is it located?
gonna try it tonight, hopefully the idle is just the screw moving as it was ticking over perfectly at 900 yesterday untill i drove it down the motorway then it started to rise.
Cheers

Steve

Hi moreno

I'm no mechanic but they might be referring to the breather in the rocker cover…..there is a few rivets you have to knock out and then clean out….OR…as I did, soak in petrol for a couple of days then use a small toothbrush and clean it that way….mine came out clean as a whistle…
TC

Hi (again) Moreno
Re yr smoke…..I had smoke on start up and it turned out to the valve guide seals!! Although my tick-over was 'normal'
TC

moreno said

hopefully the idle is just the screw moving as it was ticking over perfectly at 900 yesterday untill i drove it down the motorway then it started to rise.

This is a common problem, when the rubber seal around the brass idle screw becomes old and shrunken. It allows the idle screw to open up under motorway conditions (sustained medium to high revs).

I had this issue, and a change to a newer idle screw (with a better seal) fixed it perfectly  

The breather is indeed in the rocker over on the GTI's (I believe).  Certainly worth doing in you don't know when it was last looked at (if at all).

A blocked breather filter can make you think you have bust a ring when it gets really bad…

Guys ive found the screw and can turn it by hand!
think that might be the problem with the idle sorted!!!
Thanks
Any ideas where to get a newer idle screw (with a better seal) as the revs are going back up within a couple of minutes of turning it down now?
Will have a go at cleaning the oil breather filter in the rocker cover tonight.
Failing that will get the valve guide seals and piston rings replaced.
Cheers

Steve

In 9 out of 10 cases it a blocked breather filter.

Have a look in your yellow pages for anywhere that is a bosch service centre or fuel systems specialist and they're bound to have an idle screw lying about.  If you can turn it by hand its porbably a bit too loose.

will definatley give that breather a try
let you know how i get on tomorrow

thanks guys

Steve

Theres a little rubber o ring that keeps the idle screw tight.

Get a new o ring  from VW or stick a bit of thread lok on it.

Peter

Thread lock - thats the way to do it!

I once tried to buy some from a store in Wakefield and they had no clue what I was going on about…

Steve_Matthews said

Thread lock - thats the way to do it!…

If you can't find threadlock anywhere (try a model shop that deals with RC models - Particularly Nitro powered ones!), you can use superglue - don't worry it isn't that strong that you'll never undo it again!

Will be a good temporary fix, though I would try and get the right o'ring when you can.

ok guys this is confusing me
went out this morning and it was ticking over at 1500 then down to 900 after a couple of minutes just fine and dandy. But by the time i got to work they were at 1800.
After work they were fine again at 900 but by the time i got home they were up at 2000k.
When i popped the bonnet up there is a 'tssssssss' sound coming from around the top of the rocker cover.
If one of the pipes around the manifold/rocker cover was split would this cause the idle to increase when the engine gets warm?
Cheers

Steve

moreno said

ok guys this is confusing me
went out this morning and it was ticking over at 1500 then down to 900 after a couple of minutes just fine and dandy. But by the time i got to work they were at 1800.
After work they were fine again at 900 but by the time i got home they were up at 2000k.
When i popped the bonnet up there is a 'tssssssss' sound coming from around the top of the rocker cover.
If one of the pipes around the manifold/rocker cover was split would this cause the idle to increase when the engine gets warm?
Cheers

Steve

Yes, you should examine the grey Y-shaped plastic part over the left end of the cam-cover (as viewed from the front) - if is this part is coming apart, your revs will go up as more air gets into the engine. If this part seems good, examine all other areas of the vacuum system, as (unmetered) air getting in will make your mixture too weak, as well as messing up the idling.

My car was doing exactly the same when i bought it. Id find that like you motorway driving or a quick burst of speed would whack the revs up. It happened twice where the screw unscrewed to make that hissing sound you mentioned. All i did was screw it back in a bit and dropped the revs, but my seal needed replacing n once done it revs  perfectly at 800-900.

Im not great mechanically but it sounds exactly  like what mine was doing.

Hope that's some use.

Lewis.

Cheers Lewis that is exactly what its doing, im picking up a new idle screw and seal from vw tonight along with some other bits so ill have a go this weekend. Is it any trouble getting the seal out, does the throttle body need to come of to get at it from the inside? how do u do it?

Back in the the Jetta (1800 Carb Mk2) till i get it sorted  :cry:   good car but not as many smiles per mile as the Gti
Cheers

Steve

The seal should be on the idle screw so no need to take off the manifold - should be 5 min job :temps fate: