ballcock Posted September 14, 2011 Share Posted September 14, 2011 Help and advice needed. I changed my 3.9 v8 serpentine engine as the old one requires some work. Replacement engine 73000 miler. Before fitting decided to give it a clean as the valley gasket was leaking oil. Replaced valley gasket, drained sump, although oil dirty no apparent debris. Fitted engine. Refilled sump new filter. Started with little problem. Ran up to temp. Checked for leaks all ok running sweetly. Ran for 30 mins or more seemed perfect. Went for a spin 10 min run still ok. Took out for a run later about 10 mins into run hydraulic tappet started tapping away not too loud but there continued intermittently would then clear. Started getting slowly worse but would clear and run perfectly. Decided to give it another oil change so dumped sump contents whilst hot refilled with fresh 10w40 and another filter. Problem still there and now have to keep revving the engine to keep the pressure up. Have tapped the pressure relief valve spring retainer back up its hole to try to ensure it's not sticking with no effect. So a few questions. Does the crank driven oil pump have problems with low pressure? Does the pressure relief valve cause problems sticking? Do you need to bleed the oil cooler pipes and if so how? If I've crossed the oil cooler pipes will this have a detrimental effect and which pipe goes where? Or am I barking up the wrong tree missing something obvious? Thanks in advance Tom. Quote Link to comment Share on other sites More sharing options...
Tanuki Posted September 14, 2011 Share Posted September 14, 2011 What pressure are you seeing? Are you using a reliable mechanical oil-pressure gauge, or just depending on the idiot-light? Have you changed the oil-filter? Have you checked the condition of the mesh screen on the end of the oil-pickup pipe in the sump? [On the last Rover V8 I had in pieces, the pickup screen was choked solid with bits of old rocker-cover/valley-gaskets, flakes of gasket-sealant, lumps of snot and an evil tarry oil-residue. That was after 70,000 miles. There was a lot more black snot in the crevices of the cylinder-heads. Turned out the previous owner had run it for 10,000 miles without a thermostat to cure an 'overheating' problem which was actually due to a failed voltage-stabiliser in the instrument-pack. The ECU had been overfuelling because it thought the engine was still warming-up]. Quote Link to comment Share on other sites More sharing options...
big tim Posted September 14, 2011 Share Posted September 14, 2011 I had a simalar problem to yours mine. Turned out to be the oil pick up pipe had come loose not had a problem since Quote Link to comment Share on other sites More sharing options...
landy V8 Posted September 14, 2011 Share Posted September 14, 2011 might help if you have the right oil. you need to run 20/50 mineral. doesn't matter what the Halfrauds oil book says even tho it says 10/40 semi. might be worth dropping the sump/oil strainer off and cleaning it out .then take off the oil pump and clean it thoroughly making sure everything moves freely in the housing.also check for deep scoring in the face where the pump gears are. if they are ok then pack them with petroleum jelly and tighten it all back up. replace oil. take the plugs out and turn it over until the oil light goes out then,plugs back in and fire it up. Quote Link to comment Share on other sites More sharing options...
ballcock Posted September 14, 2011 Author Share Posted September 14, 2011 Thanks for the replies. Two new filters haven't checked pick up pipe will drop the sump tomorrow and see what I find. Didn't think of that although the engine I'm currently stripping to rebuild had lost one of the bolts on the pick up. Quote Link to comment Share on other sites More sharing options...
p76rangie Posted September 14, 2011 Share Posted September 14, 2011 Are you sure it is tappet noise? Tappet noise will usually be worse when the engine has just started, not after it has warmed up. It sounds like you put a secondhand motor in it. What do you know about it. Noises after it warms up often means issues with the motor, eg, slipped liners, worn rockers, etc. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted September 15, 2011 Share Posted September 15, 2011 I vote 20W50 as a 1st attempt. Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted September 15, 2011 Share Posted September 15, 2011 I have seen the outer rotor of the oil pump crack into 3 pieces causing low oil pressure.But as said tapping when warm is more likely worn rockers/shafts. 10/40 or 15/40 is not going to hurt a Rover v8,they need volume, not pressure so you could say that the thinner oil will get there quicker. A mechanical gauge hooked up to see what ACTUAL pressure you have would be my first action. Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted September 15, 2011 Share Posted September 15, 2011 Mr Eales is also a voter of decent oil Vavoline VR1 is his 1st choice, and is not that expensive I have used it since he recomended it for all V8s, and it does make a huge difference Start with new proper oil, then see from there Nige Quote Link to comment Share on other sites More sharing options...
ballcock Posted September 15, 2011 Author Share Posted September 15, 2011 I had a simalar problem to yours mine. Turned out to be the oil pick up pipe had come loose not had a problem since Give the man a cigar. Just dropped the sump loose pickup pipe not by much though, fitted my other one (as I had already cleaned it) refitted, refilled, started, pressure up, took for a run warmed through, tappets now silent. Many thanks for the advice. Tom Quote Link to comment Share on other sites More sharing options...
Range Rover Blues Posted September 16, 2011 Share Posted September 16, 2011 That would have been my guess, sometimes pick-up pipe problems clear when the engine is stationary as the cack drops back down, it gets sucked up once the engine starts back up. In your case it was probably as the oil heated up and got thinner too. The serpentine engine has a much better oil pump but IIRC you can't buy a new pump without a front cover, the interim cover is a bit rare. I don't agree that V8s HAVE to run on 20/50, later engines were built to run on 10/40 and the clearences are appropriate. The 4.0 and 4.6 have larger journals with tighter clearences still to run on thinner oil (larger bearing surface and higher surface speed). In fact Hydrodynamic lubrication relies very little on the viscosity of the oil, as said above it's more important that there is a good supply. Thick oil is more benificial to the topo end which relies more on boundary lubrication. I used to like 15w/50 but I have found out that modern oils rely heavily on additives to get the numbers up. The additives break down and you end up with a fairly thin oil, the the wider the range the more additives, the more it can break down. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted September 16, 2011 Share Posted September 16, 2011 RRB - Although I'm sure the engine has no great problem with thinner oils, I do think the older-style oil pump has problem sucking up thinner oils, especially if it manages to un-prime itself. Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted September 16, 2011 Share Posted September 16, 2011 RRB - Although I'm sure the engine has no great problem with thinner oils, I do think the older-style oil pump has problem sucking up thinner oils, especially if it manages to un-prime itself. I had to laugh last night as i overheard a comment on "Watchdog" where they were busy attacking a company who apparently were doing dodgy engine rebuilds.One of their bits of evidence was that "They" had packed the oil pump with vaseline,"so it would never work again"......... Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted September 17, 2011 Share Posted September 17, 2011 Give the man a cigar. Just dropped the sump loose pickup pipe not by much though, fitted my other one (as I had already cleaned it) refitted, refilled, started, pressure up, took for a run warmed through, tappets now silent. Many thanks for the advice. Tom Mmmmmm, heard and seen this before, not a common problem more a 'Tom Jones' type of problem Nige Quote Link to comment Share on other sites More sharing options...
ballcock Posted September 17, 2011 Author Share Posted September 17, 2011 Mmmmmm, heard and seen this before, not a common problem more a 'Tom Jones' type of problem Nige Do you mean " It's not unusual " Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted September 17, 2011 Share Posted September 17, 2011 Do you mean " It's not unusual " Thats what I thought he meant. Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted September 18, 2011 Share Posted September 18, 2011 Aye Quote Link to comment Share on other sites More sharing options...
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