puttputt Posted March 8, 2012 Share Posted March 8, 2012 Hi, Yesterday afternoon my Mum's 66000 mile 2000 'V' Range 4.6 V8 HSE overheated. The AA duly recovered her home, diagnosing it with a coolant pressurising fault. So filled it with coolant and run it up to temperature in the garage and it went into the red. The top hose is also solid. It occasionally has a faint misfire when first starting (this is not a car I start everyday) otherwise runs well. Already replaced the heater o rings (1500 miles ago) which suggests there is a pressure issue prior to this overheating. No visible leaks I am ssuming it needs a new block based on these series of events. Is this a fair assumption? Quote Link to comment Share on other sites More sharing options...
puttputt Posted March 12, 2012 Author Share Posted March 12, 2012 Sirs, Conducted a compression test this afternoon, warm engine, all plugs out and no throttle. Always taught plugs out WOT, lack of hands meant no throttle avail. Compression test results show two weaknesses as follows: Starting from the front of the car: Drivers side: 180, 155, 180, 180 Passgr side: 178, 170, 180, 120. Who is the best machine shop to weld and cut for liners? Many Thanks. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted March 12, 2012 Share Posted March 12, 2012 I wouldn't assume a new block at all, far too many V8s are scrapped because of supposed liner problems... Your figures suggest one, if not two head gaskets gone, get the heads off and have a looksie -I'd suggest sooner rather than later as water does tend to make a nasty mess of cylinder bores and valves Quote Link to comment Share on other sites More sharing options...
puttputt Posted March 12, 2012 Author Share Posted March 12, 2012 Cheers Bowie, if your sure to be sure I'll have a poke. 'Twas using water yet the plugs were all perfick. Quote Link to comment Share on other sites More sharing options...
puttputt Posted March 12, 2012 Author Share Posted March 12, 2012 Should also add. The intial overheat (last week) was during a 24 mile roundtrip, after approx 15 miles. The following day when tested; it overheated as the thermostat opened ish. And today before the compression test, the car was was washed and left idling for 'a not insufficent length of time', approx 1 hour and could not be made to overheat. Plugs were dry just lacking compression on two cylinders, one on either bank, so assume any water would have evaporated. The top hose was not solid either. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 13, 2012 Share Posted March 13, 2012 Everyone assumes new block with those, can be as simple as a stuck thermostat or dead head gasket. Start with the cheap stuff! Quote Link to comment Share on other sites More sharing options...
p76rangie Posted March 13, 2012 Share Posted March 13, 2012 It is usually the rear cylinders that will blow the gasket. By the rear passenger side only being 120 psi, there is a very good chance that you have done the head gasket at that cylinder. If it was a slipped liner, you would hear it once the motor warmed up. Quote Link to comment Share on other sites More sharing options...
puttputt Posted March 13, 2012 Author Share Posted March 13, 2012 'FridgeFreezer' Everyone assumes new block with those, can be as simple as a stuck thermostat or dead head gasket. Start with the cheap stuff! Thankyou. will test the thermostat. Given the odd compression readings on the drivers side what do you suppose? There is no tapping (a slipped liner signal) when wam)? 'p76rangie' It is usually the rear cylinders that will blow the gasket. By the rear passenger side only being 120 psi, there is a very good chance that you have done the head gasket at that cylinder. If it was a slipped liner, you would hear it once the motor warmed up. Thankyou, it does seem odd that the warp is in the the middle of the driver side rather than the normal 'end' as per the passenger side. The noise the liner will make. from research, is suggested to be a tapping noise when warm; there is no tapping noise to be heard only a slightly vocal idler pulley bearing (to be replaced in due course). What is wrong with the original head gaskets? . Will take heads off next week. Many thanks to all. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted March 13, 2012 Share Posted March 13, 2012 Given you have low readings on both banks, I would strip them both off and replace, then once you have it up and running again, get the coolant tested for gasses, or buy a kit yourself, they are only about £35 on ebay and means you can test over and over, and be sure the block is OK. http://www.ebay.co.uk/itm/BT500-TEST-TOOLS-BLOCK-TESTER-KIT-/400204873011?pt=UK_Hand_Tools_Equipment&hash=item5d2e11bd33 Something like this, although I am pretty sure I found mine slightly cheaper elsewhere. The test takes about 5 minutes from a warm engine. Quote Link to comment Share on other sites More sharing options...
p76rangie Posted March 13, 2012 Share Posted March 13, 2012 What is wrong with the original head gaskets? The coolant passes from the block to the heads at the rear of the engine on each bank of cylinders. The coolant, or lack of it, can affect the head gasket causing a leak either to the outside or to the rear cylinders. A head gasket can go between cylinders, but you would have had two cylinders next to each other with low compression. Which you don't have. So the lower reading on the drivers side is either an inaccurate reading or something like valves not sealing proper. Unlikely to be a head gasket issue. It is also best to replace the head bolts with ARP studs to help avoid any problems in the future. Quote Link to comment Share on other sites More sharing options...
puttputt Posted March 13, 2012 Author Share Posted March 13, 2012 Given you have low readings on both banks, I would strip them both off and replace, then once you have it up and running again, get the coolant tested for gasses, or buy a kit yourself, they are only about £35 on ebay and means you can test over and over, and be sure the block is OK. http://www.ebay.co.uk/itm/BT500-TEST-TOOLS-BLOCK-TESTER-KIT-/400204873011?pt=UK_Hand_Tools_Equipment&hash=item5d2e11bd33 Something like this, although I am pretty sure I found mine slightly cheaper elsewhere. The test takes about 5 minutes from a warm engine. Thanks, who do you recommned for the gaskets? p76 Rangie: The coolant passes from the block to the heads at the rear of the engine on each bank of cylinders. The coolant, or lack of it, can affect the head gasket causing a leak either to the outside or to the rear cylinders. A head gasket can go between cylinders, but you would have had two cylinders next to each other with low compression. Which you don't have. So the lower reading on the drivers side is either an inaccurate reading or something like valves not sealing proper. Unlikely to be a head gasket issue. It is also best to replace the head bolts with ARP studs to help avoid any problems in the future. Again thanks, who do you recommend for the studs? Quote Link to comment Share on other sites More sharing options...
p76rangie Posted March 13, 2012 Share Posted March 13, 2012 Thanks, who do you recommned for the gaskets? who do you recommend for the studs? I do not keep a record of brand names on gaskets. I simply buy them from someone I trust and I know will sell me good stuff. There are basically two main theories about why head gaskets on Rover V8s fail. One believes it relates to overheating the motor. The other believes that it relates to incorrect tensioning of the head. The coarse threads required for a alloy block make it difficult to get all the tensions on the bolts exactly the same. Studs get around this by having a nut with fine threads on a steel stud. So if the gaskets go because of incorrect tensions, then studs will help save your gasket in the future. The theory of bolt tension was also support by the fact that gasket failures reduced dramatically when they shifted to torque to yield bolts. TTY bolts are better in obtaining even and correct tensions, but still not as good as studs. Quote Link to comment Share on other sites More sharing options...
puttputt Posted March 21, 2012 Author Share Posted March 21, 2012 Having read arguments for both, Is it OK to remove the heads cold? Your thoughts please Gentlemen. Quote Link to comment Share on other sites More sharing options...
puttputt Posted March 24, 2012 Author Share Posted March 24, 2012 Removed the passenger side head. Gasket OK. Soot on low comp cylinder valves, others looked right for the miles and were light tan in colour. Cam was noisey when cold, some tappets (not with car at present) were hollowed from use, pushrods looked OK. So low comp from warn cam? Water pressure and coolant loss from something else? Drivers head to be removed. Will update further. Quote Link to comment Share on other sites More sharing options...
puttputt Posted March 31, 2012 Author Share Posted March 31, 2012 Removed drivers side head, everything looked OK. Will I incur forum wrath if re-use head gaskets and exhaust gaskets (60D type engine)? Put thermostat in kettle to test. Opened a few mm thus allowing some flow. Should they open as far as the spring allows? Many Thanks, Putt putt. Quote Link to comment Share on other sites More sharing options...
SteveRK Posted April 1, 2012 Share Posted April 1, 2012 Sounds like you have jumped in at the deep end in stripping the engine before checking to easier first test items. Thermostats don't open very much, maybe 2mm, but equally as importantly they should open before the water starts bubbling/boiling, the 'stat will have the temperature number stamped on it usually so you need a thermometer to test the water temp when it opens. A 'stat opening around boiling point will likely cause overheating in the engine. Did you check that the water pump impeller is not sheared and also for any blockages in the radiator or other water channels that need to conduct the flow of water when the 'stat opens? Quote Link to comment Share on other sites More sharing options...
puttputt Posted April 2, 2012 Author Share Posted April 2, 2012 Thanks Steve, Yes you are probably right. At least it has enabled us to find the cause of low compression and we get to fix a water leak to boot. Every cloud etc. The numbers are 66a gf 30, will do other checks in due course. Quote Link to comment Share on other sites More sharing options...
geoffbeaumont Posted April 2, 2012 Share Posted April 2, 2012 Will I incur forum wrath if re-use head gaskets and exhaust gaskets (60D type engine)? Err... Yes! Once the gaskets have been compressed they aren't reusable (but neither are they very expensive). Always replace them, even if they look fine. Quote Link to comment Share on other sites More sharing options...
Cynic-al Posted April 3, 2012 Share Posted April 3, 2012 I find its often worth changing the rad cap for what they cost too, i've had a couple of cars where these have gone. Quote Link to comment Share on other sites More sharing options...
puttputt Posted April 13, 2012 Author Share Posted April 13, 2012 Removed the water pump which was as new (in keeping with all findings thus far).. Genuine part quote: Head Gaskets, bolts, inlet manifold, exh manifold, downpipe and w/pump: £187.74. Have there been any bad reports on the £60 ebay camshafts and lifters? Many Thanks. Quote Link to comment Share on other sites More sharing options...
puttputt Posted April 17, 2012 Author Share Posted April 17, 2012 Is it worth skimming the heads? (gaskets didn't blow). Quote Link to comment Share on other sites More sharing options...
geoffbeaumont Posted April 18, 2012 Share Posted April 18, 2012 Might be worth getting them checked, given it's overheated, but don't skim them unless they actually need it as it affects alignment between the head and the inlet manifold and also alters the compression ration (though in both cases you probably wouldn't have any problems with a mild skim). No idea about the cheapy cam and followers, but personally I'd be wary - if they're rubbish you'll end up stripping the engine down again to change them. If you're going to cut cost, do it on bits that are easy to change! I think the standard cam is only around £60 anyway? Quote Link to comment Share on other sites More sharing options...
puttputt Posted April 19, 2012 Author Share Posted April 19, 2012 Geoff thanks, Have found the £60 ones on ebay (cam), can you source genuine for that? Quote Link to comment Share on other sites More sharing options...
geoffbeaumont Posted April 25, 2012 Share Posted April 25, 2012 Not sure whether or not that's genuine - I just had a quick look on MM4x4's website, which doesn't specify manufacturer. You'd need to give them a call to find out if it's genuine. Some genuine LR parts are actually fairly inexpensive so it may be. Quote Link to comment Share on other sites More sharing options...
puttputt Posted May 9, 2012 Author Share Posted May 9, 2012 Straight edge ordered results to follow... Quote Link to comment Share on other sites More sharing options...
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