compression test results what do they mean
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compression test results what do they mean
1=furthest from radiotor
1.=10psi
2.=9psi
3.=0psi
4.=13psi
i think its probably head gasket am i right
bought compression tester from halfords for 19quid and ran test myself
i also get brown gunk in top of rad water
thanks
1.=10psi
2.=9psi
3.=0psi
4.=13psi
i think its probably head gasket am i right
bought compression tester from halfords for 19quid and ran test myself
i also get brown gunk in top of rad water
thanks
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8ball - Posts: 1101
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RE: compression test results what do they mean
Are you sure you are doing the test right or reading the results in Bar rather than psi because with compression figures so low the engine shouldn't run at all!
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minimaniac - Contributor
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RE: compression test results what do they mean
Actually no. 1 cylinder is the nearest to the rad - you've numbered them backwards!
But anyway these figures are terrible..really terrible..as in... really really terrible.
You should get 150-190psi
Even with a blown head gasket you should get a lot more than this maybe 50?
Normally when the gasket blows you get say
1=180
2=50
3=70
4=160
In this case it's blown between 2 & 3 - ( the most common.)
Are you positive you're using it/reading it right??
You should remove all the plugs,
screw tester in - make sure the rubber 'o' ring is a snug fit.
open the throttle all the way
crank engine, the reading should stabilise after a few secs.
But anyway these figures are terrible..really terrible..as in... really really terrible.
You should get 150-190psi
Even with a blown head gasket you should get a lot more than this maybe 50?
Normally when the gasket blows you get say
1=180
2=50
3=70
4=160
In this case it's blown between 2 & 3 - ( the most common.)
Are you positive you're using it/reading it right??
You should remove all the plugs,
screw tester in - make sure the rubber 'o' ring is a snug fit.
open the throttle all the way
crank engine, the reading should stabilise after a few secs.
- Dino
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RE: compression test results what do they mean
Oh, the brown gunk does suggest it may be the head gasket BTW
- Dino
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RE: compression test results what do they mean
Those reading better not be in PSI !!!!!!
Anyway I'll base this answer on you getting your units wrong. Yes you have no compression on number 3 cylinder.
Does your rad bubble a lot when running with cap off or a lot of steam in the exhaust (heavy water consumption). If so then the likelyhood is you've blown the had gasket. (You'll probably find white mayo in the oil cap too).
If not then you could have a valve problem. Burnt valve, something stuck in it etc etc. You could also have damaged rings/piston.
...But first of all check the readings on your guage.
Stoo
Anyway I'll base this answer on you getting your units wrong. Yes you have no compression on number 3 cylinder.
Does your rad bubble a lot when running with cap off or a lot of steam in the exhaust (heavy water consumption). If so then the likelyhood is you've blown the had gasket. (You'll probably find white mayo in the oil cap too).
If not then you could have a valve problem. Burnt valve, something stuck in it etc etc. You could also have damaged rings/piston.
...But first of all check the readings on your guage.
Stoo
- Stoo
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RE: compression test results what do they mean
you sods beat me !
- Stoo
- Posts: 154
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RE: compression test results what do they mean
ok those readings are bar
by throttle all the way open do you mean gas pedal to the floor and i only took out the plug i was testin
by throttle all the way open do you mean gas pedal to the floor and i only took out the plug i was testin
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8ball - Posts: 1101
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Re: RE: compression test results what do they mean
"8ball"]ok those readings are bar
That's a relief!
Take out all the plugs and try it again. Number 2 (your number 3) should at least show some reading even if there's a hole in the piston! Once you've tried it squirt a little oil (not a lot) through the plug hole and try it again. If it improves then it's normally the piston rings, if it doesn't then it's a valve or gasket problem.
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minimaniac - Contributor
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Re: RE: compression test results what do they mean
Dino wrote:Oh, the brown gunk does suggest it may be the head gasket BTW
Yep, also check for water coming out of the exhaust and A LOUD "CLANKING" UNDER LOAD!!!!
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alloying - Posts: 1594
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rhubarbin gr8
tried the oil thing and psi increase from 10 to 50 on 3 tried it on 4 aswell now my gauge wont work and my car wont start if i hav the spark plug in 4
wot the rhubarb do i do now
wot the rhubarb do i do now
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8ball - Posts: 1101
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RE: rhubarbin gr8
8ball, when it was driving did it "clank" under load i.e. when you put your foot down????????? (I've asked you about 4 times now).
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alloying - Posts: 1594
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RE: rhubarbin gr8
Just for reference, your original readings in psi are approx;
4. 145
3. 130.5
2. 0
1. 188.5
1 bar is approx 14.5 psi
4. 145
3. 130.5
2. 0
1. 188.5
1 bar is approx 14.5 psi
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pablo - Posts: 557
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RE: rhubarbin gr8
8ball, when it was driving did it "clank" under load i.e. when you put your foot down????????? (I've asked you about 4 times now).
sorry mate dont think it clanks is definatly noiseyer and has lost power struggles up hill
latest readings are
150 psi
130 psi
10 psi
190 psi
with drop of oil in spark plug whole 10 psi increases to 60
have managed to start car now even tho i carefully labelled the leads i put 3 and 4 the wrong bloody wrong way round wot a numptey
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8ball - Posts: 1101
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RE: rhubarbin gr8
Hmn, what about a "ticking" noise? listen carefully to the cylinder with the bonnet open.
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alloying - Posts: 1594
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RE: rhubarbin gr8
Either a sticking rocker/valve, burnt valve, or a hole in the piston!
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ceejam - Posts: 10876
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RE: rhubarbin gr8
how do i check the valves
it does sound like a ticking or tappin noise
Hmn, what about a "ticking" noise? listen carefully to the cylinder with the bonnet open.
it does sound like a ticking or tappin noise
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8ball - Posts: 1101
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RE: rhubarbin gr8
Sounds like a piston ring!
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alloying - Posts: 1594
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RE: rhubarbin gr8
that sounds hard to fix or check is it
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8ball - Posts: 1101
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RE: rhubarbin gr8
You need to take the head off to see what is wrong.
It could just be the headgasket, they can fail in such a way as to create a 'one-way flap' between two cylinders, i.e. you will get a pressure reading in one but not in the other.
It could just be the headgasket, they can fail in such a way as to create a 'one-way flap' between two cylinders, i.e. you will get a pressure reading in one but not in the other.
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Jimmyarm81 - Posts: 434
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RE: rhubarbin gr8
think ill go get a head gasket now how long does it take to do roughly ive got my haynes manual to talk me through it
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8ball - Posts: 1101
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RE: rhubarbin gr8
Took me about 5 hours first time round. Now I can do it in about 20 mins (lots of practice lol).
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alloying - Posts: 1594
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RE: rhubarbin gr8
Tip: the hardest part is trying to get the exhaust manifold off (especially if it's an LCB or freeflow), so undo the top engine steady from the engine and that should give you the clearance you need to pull the exhaust manifold out the way.
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alloying - Posts: 1594
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RE: rhubarbin gr8
rite im gunna go and have a go now with with the help of a light and my brand new torque wrench. hopefully i can get it done tonight or ill have to finish it 2morra mornin b4 work
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8ball - Posts: 1101
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RE: rhubarbin gr8
good luck
my guess is that if its your first one you wont manage in time. not meaning to have a pop mate, its just that if you do it well the cleaning up will take you a couple of hours alone. if you have the head off i would clean up the valves and reseat them as well.
my guess is that if its your first one you wont manage in time. not meaning to have a pop mate, its just that if you do it well the cleaning up will take you a couple of hours alone. if you have the head off i would clean up the valves and reseat them as well.
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Zippyrude - Contributor
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RE: rhubarbin gr8
oh and you will need feeler gauge to set the tappets / valve clearance.
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Zippyrude - Contributor
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RE: rhubarbin gr8
It's more than just the head gasket - most likely a valve, better hope it's not rings or piston - but that would have blown much oil fume out the breathers. Best bet would be to get hold of another head - and just swap them over. Even that for a first timer is going to take a good few hours.
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royallingham - Posts: 10246
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RE: rhubarbin gr8
am pretty proud of the cleaning ive done
im exhausted now so had to pack up but head is on and torqued up jus everythin else left to do now to put it back together
balls didnt do anythin with the valves part from clean round them some were a bit black will see how it is 2morra and next time i got a whole day will do valves if need be
im exhausted now so had to pack up but head is on and torqued up jus everythin else left to do now to put it back together
balls didnt do anythin with the valves part from clean round them some were a bit black will see how it is 2morra and next time i got a whole day will do valves if need be
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8ball - Posts: 1101
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RE: rhubarbin gr8
Was the gasket blown?
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alloying - Posts: 1594
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RE: rhubarbin gr8
last time i seen this, i did a leakdown test and found that the rings were shot.. :\
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icklemini - Posts: 2919
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RE: rhubarbin gr8
gasket seemed ok bit thin tho no damage i could see
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8ball - Posts: 1101
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RE: rhubarbin gr8
Did you check the bores?
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alloying - Posts: 1594
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RE: rhubarbin gr8
if by bores you mean the were the pistons run then they were smooth as a babies bum no burns or anythin. was sum crap on top of pistons but clean that up inside the head was a little sooty will do another compression test 2morrato see how it is
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8ball - Posts: 1101
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