myke
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Registered: 7th Feb 01
Location: High Wycombe, Buckinghamshire
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heads been doing funny things for a while now and i broke down/overheated on sunday.
a sniffer test showed there were combustion gases in the coolant which aa man says meant the head gasket was fubar.
i wasn't too sure whether it would be the head or the gasket or something worse lower down, but i've done a compression test this evening and it doesn't look good.
1 105
2 54
3 51
4 80
these were from cold as the engine wouldn't run and i totally forgfot to do a wet test untill after i'd started ripping it to pieces, so these are the only figures i have, but does anyone know what they might point toward being the problem?
going to change the head over anyway so the gasket will probably reveal all, but could it have damaged the rings or anything?
cheers
[Edited on 07-09-2005 by myke]
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Mistamist
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Registered: 16th Jul 03
Location: Gillingham, Kent
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crack in the head?
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miles
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Registered: 25th Mar 02
Location: plymouth Drives: Astra Sport
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All 4 figures are poor, with 2 being obviously worse. Doesn't really seem to point to one failure in particular.
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myke
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Registered: 7th Feb 01
Location: High Wycombe, Buckinghamshire
User status: Offline
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so could the head just be crap, or is it morelikely the gasket?
heads been ported and polished, then found to be porous.
v-tuning supposedly fixed the porousityt 'for life' at christmas, but i've been plagued with oil in my water ever since.
i'm not sure if it's a crack in the head or wether the porous prob was never fixed right, but i think the oil in the water has beeen causing blockages which in turn has caused the engine to run hot.
evntually it's overheated( perhaps the temp gauge has been coated in emuslsified oiil aswell and not been giving a true figure of collant temp) and perhaps the gasket is now shot because of running high temps.
my coolant stat to rad hose i've noticed tonight is split where it's been sat on one of the bosy mount bolts. i'm unsure if the oil has eaten through the rubber causing the split or if the heat/pressure from the water is the reason behind it but there is a definate split in a sub-year-old hose.
a couple of the other hoses are ballooned also. mainly the hard pipe (round the back of the engine) to the ns of the rad. i'm sure this is because of the silly pressure my coolant system has been running, buyt i'm wondering whether to totally replace all of my coolant hoses and the rad of to just clean everything out as best as possible and then hope for the best in future months.
i've been told before that oil will eat through rubber, but how quick does it act?
should i riskj re-using my hoses or replace al with new at great expense@?
cheers
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myke
Member
Registered: 7th Feb 01
Location: High Wycombe, Buckinghamshire
User status: Offline
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to add to your replies guys,
the head has been porous repaired which is supposedly for life, but the problem still exists which would possibly point to a cracked head ?!?!?!  hi ben
and the comp test was done when engine was cold when giuides instruct a warm engine when conducting tests (obviously not possible under the circumstances). i don't know to what extent the heat of the engine would effect compression test results, but obviously my figures are too far out to be just temp dependant.
what's normal, 150 across all four? i'm just not sure of the diff temp would make between 105 on the 'good' cylinder to whatever is a reasonable figure when warm.
thanks
myke
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Mistamist
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Registered: 16th Jul 03
Location: Gillingham, Kent
User status: Offline
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Myke lemme know if you need a new head as i may be able to get hold of one.
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Jake
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Registered: 24th Jan 05
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did you not get a guarentee on the fixed head?
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fragpot
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Registered: 29th Feb 04
Location: Linlithgow, West Lothian
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I think head gasket failure caused by a warped head. All 4 cylinders are low but the 2 middle cylinders are even lower so it may well be warped. A skim should sort that out if it is. Then buy a cometic gasket off me  Would be a shame to waste a ported & polished head with porus fix. Coscast heads cost a fortune and whos's to say your new head wont be porus.
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myke
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Registered: 7th Feb 01
Location: High Wycombe, Buckinghamshire
User status: Offline
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the one waiting to go on is a coscast so i'm hoping it should be healthy, but i'll take them both for a check up before doing anything with them.
the company that fixed the porous one was v-tuning who are now out of business due to a workshop fire, so i can't even take it back there. 
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myke
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Registered: 7th Feb 01
Location: High Wycombe, Buckinghamshire
User status: Offline
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got the head off tonight and the gasket is absolutely fine.
thecentre bolts 9 and 10 in the sequence didn't seem to be very tight and i know 100% they were torqued to the book back in january.
also these two bolts seemed very oily and there was a load of oil between the head and the block between pots 2and3.
any ideas?
i'll seperate the manifold from the ehad tomorrow and take it somewhere for testing.
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ainsley_brader
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Registered: 24th Mar 02
Location: Tattershall, Lincolnshire
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oil degrades the rubber hoses causing them to split. If they feel very squishy replace them!
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ed
Member
Registered: 10th Sep 03
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Best get the thing pressure tested Mike... Sounds like the heads got a leak...
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miles
Member
Registered: 25th Mar 02
Location: plymouth Drives: Astra Sport
User status: Offline
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Stick a steel rule against the head face to see how flat it is.
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myke
Member
Registered: 7th Feb 01
Location: High Wycombe, Buckinghamshire
User status: Offline
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feeler gauges under a straight bar right?
what does the pressure test involve?
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ed
Member
Registered: 10th Sep 03
User status: Offline
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See's if it's gone pourus again...
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myke
Member
Registered: 7th Feb 01
Location: High Wycombe, Buckinghamshire
User status: Offline
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v-tuning's fix is supposedly 'for life'. i'd take it back to them and get them to take a look if they were still in business.
my guess now is that it's cracked which was letting through the oil and warped because of overheating because of the oil.
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