sotal Posted November 21, 2009 Share Posted November 21, 2009 Car: 4.6 V8 HSE Range Rover 1998 Cause of Problem: Coolant pipe split, lost coolant quickly, overheated. Car recovered back home. Problem now: Engine did start and run but the compression was tested on the front two cylinders and was found to be low. Drivers Side Head removed - no damage can be seen, head looks fine liners look fine, bore is fine, top of pistons look fine etc. Question: Can anyone suggest why the compression is low? What could have happened? Suggestions to fix? Or is it a new engine job? Also when looking at paddocks for some engine parts - some are listed as 4.6 v8 low compression parts and some are listed as 4.6 v8 high compression parts. Did they do two versions of the engine? If so how do you know which is which? Quote Link to comment Share on other sites More sharing options...
g&t Posted November 21, 2009 Share Posted November 21, 2009 If I have got this right you are assuming that the low comp. readings are the result of the overheating incident. Did you ever do a comp. test prior to this, if not then how can you be sure that the readings were not low before? If the engine/car runs ok I would'nt fret, at least until something else shows up like (dare I say) a slipped liner, in which case your ears will tell you! Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted November 21, 2009 Share Posted November 21, 2009 Not enough info really ………….. Did the coolant pipe split due to age or because it was pressurised by compression gases getting into the coolant system ……….. I suspect the latter…….. What was the head gasket like ? ………….. sounds like two cylinders have blown into each other and also in the coolant system …….. not at all unusual What were the cylinder compression readings ? The head (s) will need skimming as well………….. Quote Link to comment Share on other sites More sharing options...
sotal Posted November 21, 2009 Author Share Posted November 21, 2009 Thanks for the reply unfortunatley I don't have much more info, it's a car I'm in the process of buying, if it's going to cost too much to fix I'll break it for parts. Do you think from the description that it may be possible to fix? How much does head skimming normally cost? Is there any way to make sure it is needed? I was told the compression readings were low that's all, and I thought it was odd they only tested two cylinders? Only one head has been removed at the moment. My thought was to build it back up with new hg's and then start the testing again properly? I don't know much about V8's but the car is cheap and I can make money breaking it, so I figured it was worth buying but I'd like a go at fixing it first - in which case I'll use it. Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted November 21, 2009 Share Posted November 21, 2009 There is a large possibility that the head gasket has blown as liner trouble rarely (if ever) shows up as low compression readings, however, a blown head gasket will 9 times out of 10 give itself away by lost compression and this would tie in with the split coolant hose……..…….. Well, the other head needs to come off and you are looking at about £30 each for facing and about another £30 for gaskets ……… then you should be good to go. If its mega cheap then fine ………….if not then walk away Quote Link to comment Share on other sites More sharing options...
sotal Posted November 21, 2009 Author Share Posted November 21, 2009 Thanks for the help, I think it would be worth a punt at those sort of costs to see if it fixes it. Just been searching the web for similar problems to the ones you mention. I just found one where the bloke reckoned his LPG system was pressurising the Coolant and causing pipes to burst etc - is this at all likely. (I forgot to mention this one has an LPG system fitted!) Cheers Quote Link to comment Share on other sites More sharing options...
zoltan Posted November 21, 2009 Share Posted November 21, 2009 I just found one where the bloke reckoned his LPG system was pressurising the Coolant and causing pipes to burst etc - is this at all likely. Sounds like a lot of methane in his system Quote Link to comment Share on other sites More sharing options...
vougese39 Posted November 21, 2009 Share Posted November 21, 2009 other things to consider sticking valve due to over heating worn cam sticking followers now more prominat due to cooking Quote Link to comment Share on other sites More sharing options...
manxrover Posted November 22, 2009 Share Posted November 22, 2009 Hi It sounds like the head gasket, maybe the head has also cracked, with it expanding owing to the heat build up. I had simular problems with my DSE, but on advice from the forum I tried K Seal, and 10k later still running fine. Maybe you could try it as a quick fix, I did and it worked. Brian Quote Link to comment Share on other sites More sharing options...
sotal Posted November 22, 2009 Author Share Posted November 22, 2009 Thanks for the tips - I've gone for it so should (if everything goes right) have it on the drive next weekend - I will then bombard the forum with questions! Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted November 23, 2009 Share Posted November 23, 2009 Be absolutely sure to get all the engine parts that have been removed ! Quote Link to comment Share on other sites More sharing options...
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