GolfGTIforum.co.uk
General => The garage => Topic started by: Deefadog on 26 July 2004, 15:01
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Hi all i just bought a compression tester from Halfords, now I need to get the car to running temp and then disconect the coil, how do I disconnect the coil? I don't know where it is i am really stupid :) Is it where the middle ht lead comes out of?
A pic would be great :)
Also when I do the readings what should they be?
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Yes mate, its the middle one. Make sure the disconnected lead is'nt touching anything or ANYONE when you crank it. Not sure what's good but my valver was 10bar in all cylinders. Would be interested to see what you get. Its important that all the cylinders have a simlar compression too.
Cheers,
Matt.
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Cheers, so it's the middle ht lead from the coil I disconnect, yes and rap some insulating tape around it to keep everything safe? any more tips when doing this?
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You might want to wait for expert :-\ But thats all i did. Just Take one spark plug out at a time screw the compression tester in & crank the car for a few seconds take the reading, put the spark plug back & move on to the next one.
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Oh & i think there is wet & dry compression tests. I'm sure someone will tell me if i'm wrong, but the above is a dry test???? Not sure what the wet test tells you, someone here will defo know. Cheers.
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Thanks Matt
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I would not leave the coil lead open circuit as this will cause a massive voltage build up and can damage the ign amplifier :o. Recommend disconnecting the low tension wires to the coil, and when cranking the engine hold the throttle open to give the most accurate reading.
Steve.
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Thanks
Is this the coil?:
(http://www.realitydesigns.co.uk/forum images/Coil.jpg)
And if it is I have a spade free as you can see, should I have something connected here?
MK1 - When you say "Recommend disconnecting the low tension wires to the coil"
Are these the other spade connector to the coil?
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Yup, thats the coil. (nice picture ;))
Spare terminal on the coil is OK, disconnect either side and it will be OK.
Steve.
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Cheers mate, funny thing is when I came home today and let my car run on idell for a few minutes(as I always do, since ot started smoking) it did not smoke, but my mileometer stoped working, but rev counter was fine, if it aint one thing it's another :)
Happy days :)
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When i've done it before, i took the ht lead off that connects the coil and the dizzy, remove the lead completely, no problems.
Then also remove the fuel pump fuse.
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Why the fuel pump fuse, does this stop the car from becoming flooded?
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aye
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Yar.
If you don't take out the fuel pump fuse then you will get rather high compression, as the cylinders will flood with fuel :D
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Thanks, i'll do it this week, any ideas what the pressure should be on my MK2 16V?
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std should be about 180, goodun's more towards 200+
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Thanks i'll let you know when i do it, probablly friday!
take care
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Right good news here are the compression test results (I am working from left to right as I don't know which are which)
Cylinder1: 185 psi
Cylinder2: 190 psi
Cylinder3: 185 psi
Cylinder4: 185 psi
The second one was slightly higher as you can see, but not by much.
So what next? If this is a good result on a car that has done 183000 miles, where else should I look for the burning oil? remember it only appears when the engine is up to running temp and is idling, i can drive for 10 minutes or 2 hours, pull up and let the car idle, at first the exhuast is clear then after about 1 minute the smoke apears, not bellowing out but enough.
Any advice would be much appreciated as always
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Compressions are bang on, oil consumption is probably from the valve stem seals.
Steve.
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Have you cleaned the breather hoses?
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Thanks guyz.
golfvr6 - Breather hose's are all clean, was not alot in them, just a coating, the mesh was quite clean also! (should I completely remove this mesh?)
Just to check, Is there only the one breather hose right? I also cleaned the other hose which goes across the top of the engine into the airbox, that was very clean also!
MK1 - the valve stem seals, is there a way to check these? or is it a big job to replace them?
I did notice that on the new spark plugs (1 week old) that the second one from the left and the 4th one from the left had a black deposit just around the rim where the prongs come from, is this any help?
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Mine does exactly the same mate, will be following this with interest ;)
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Sounds like valve guide oil seals to me.....Hazels Audi 1.8S is doing exactly the same and the compressions are about the same too.
I have a compressor so I have just bought one of these:-
http://www.machinemart.co.uk/product.asp?p=040211463&r=2205&g=107 (http://www.machinemart.co.uk/product.asp?p=040211463&r=2205&g=107)
and one of these:-
http://www.machinemart.co.uk/product.asp?p=040211452&r=2205&g=107 (http://www.machinemart.co.uk/product.asp?p=040211452&r=2205&g=107)
In the hope that I can do the valve guide seals without removing the head. I thought the air adapter would also double quite well as a leak down tester ;)
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Not to sure I am confident enough to do that on my own :)
If a garage was to do it for me how much would I be looking at?
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I was quoted about ?200 ish. Half a days labour i'm told?
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Not too bad I guess, are you going to have it done matt?
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Is the black deposit powdery or oily? And is your smoke blue or black. Could it be dodgy injectors if the smoke is dark and doesn't smell or oil and the plugs are powdery??
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The black deposits on the two plugs are powdery!
But I think it is burning oil :(
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Hi, think i'm gonna get it done as it is slowly getting worse :'( Just out of interest does yours smoke when the engine is cold, i.e first thing in the morning?
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No mate, I do get A little white smoke, but that's just condensation like in any car!
I GET THE SMOKE ONLY WHEN THE ENGINE IS AT RUNNING TEMP AND IS LEFT IDLING (sorry about the caps, slipped and could be bother to re type it):)
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Hmm, exactly the same as mine. Think i'll get her booked in :'(
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Can't get mine done until pay day, so let me know how it goes!, pm me if you want!
cheers
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I've got a slightly iffy valve seal on my Golf and it shows up when the car has been sitting overnight as a cloud (!) of blue smoke when the car is first started. It should also show as the car decelerates and you blip the throttle back on - apparently the oil is forced to the top end of the engine when slowing down and you blip the throttle and any oil getting past the seals is burnt. Not sure about it showing just at idle though?!
Do you know what the oil pressure is when the car is hot? Just wondering if it could be forcing oil past the head gasket into the cylinders from the oil galleries only when the engine is warm - thermal expansion..?
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D'oh! Now i'm really worried! Say for example the oil pressue was too high(i have absoloutly no idea how to check this!) what sort of things could be causing it?
Sorry to hijack your thread Deefa!
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Go for it mate :) it apllies to me aswell :)
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Oops. Was just thinking out loud really. I was thinking that the classic symptoms of valve seals show up more on deceleration than at idle when the vacuum is higher (to my knowledge anyway).
Saying that the powdery black stuff suggests oil being burnt, so it's either valve seals, blocked crank case breather or something else, and I was wondering what the something else might be.
Cylinder pressure finding it's way into the oil system would probably force oil out of your dipstick hole or make a hissing noise when the stick is removed.
You sure that your PCV valve (black mushroom thing) is working ok? That being faulty would probably cause your symptoms aswell.
I think you'll find it's most likely to be valve seals.
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;D how can we check the pcv valve? & is it on or very close to the airbox or am i way out??
Cheers mate.
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Yes where is the PCV valve and how do we check it?
Looks like me and you matt have about the same knowledge, but it is fun in a sad way!
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Everyday's a school day deefa!! ;D (for me anyway)
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I expect there's a PCV on the 16v, but I don't know what it's like. Ignore what I said about mushroom thing-think it's only that shape for 8v's. Is there a rocker cover plastic shield on 16v's? On the 8v if you take it off, the oil can get into the breather system..
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Errrr, not sure. The only breather system i'm aware of is from the crank case to the air box. ???
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Any updates Matt?
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Not yet mate, just waiting for the guy who's hopefully going to do it.Looks like it could be more expensive than i first thought, i'm now told the head may need to come off to do it. I'll keep you you posted Deefa.
Cheers mate,
Matt. 8)
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Just got a qoute from my guy, ?247 including the VAT. Well chuffed with that!
Will get it booked in ASAP
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Nice one mate, let us know how you get on, How long will it take?
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Should get it back on wednesday, of course he will not be able to tell if it's the valve seals untill the head is off, hopefully it is just them :)
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Can't see it being anything more serious, everyone i've spoke to, including 3 mechanics! Reckons mine is the stemies & it has exactly the same symptoms as yours.
All the best mate, let me know what happens.
Cheers,
Matt. 8)
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Getting her back on thursday :) good news is that he said the stem seals were badly worn, I could not of bared it if they were fine :) also getting a new timing belt fitted while he is at it, peace of mind and all :)
I'll let you know on thursday how she is.
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Thats good news mate ;D
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Alreet Deefa! How's the motor now :D
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:) Well no smoke, she seems great now and alot more power especially between 1000 & 2000 revs, where before was really slugish!
Cost ?350 in the end with the new belt and tensioner (the old belt was ready to fall off, really lucky). Well happy
Got to get her on a long run now and really test it but looking good so far, I'll let you :)
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;D 8) :D
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Took her for a long run this morning, pulled over in work and let her idle for ages, no smoke :)
Idling is a bit high is around 1100, so i'll get him to sort this out later.
Fuel consumption has really improved, my usuall motorway drive gave me 26mpg on average, today i got 34 :)
The work should pay for it self in around 100 years :)
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;D Thats good news matey.
I know i've asked you this before, but can i just compare my symptoms to what you had. So i can be as sure as pos before i start throwing money at her!
1. No smoke when cold
2. No smoke straight after driving, but smoke after a couple of mins of idling
3. Smoke on startup when warm, say after filling up.
Cheers mate.
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Yep all the symptoms, but can't confirm No 3 as I never notice :)
But whatever happens it's blowing smoke and the only way to see what's worn and what has not worn is to take the head off, aslong as you have checked all the other things that could cause it like blocked breathers etc.
Head gasket set and bolts were about ?65, labour was ?150 as it's quite a time consuming job.
Hope you get yours sorted soon
Take care and let us know