4.6 Oil Pump ?

[Jezzaol]

My 4.6, Since We did it up a couple of years ago has had low oil pressure at idle, The light comes on sitting at lights etc, you give it a rev or hold the rev's up and the light goes out !
I know the oil pump is in the timing cover with odd looking gears and a spring from memory but that's as far as my knowledge goes:p
I have the Engine out at them moment and I think it might be a good time to overhaul or fix this problem ??
Can anyone tell me what needs to be done ? Can you buy a kit ? What fails in there ? Is there a pressure release valve ?

Cheers and thanks in Advance !
Jeremy

[p38arover]

The pressure relief valve is in the cover near the oil pressure switch.

The pump is non-serviceable. You have to buy a new timing cover and pump.

Late edit: June 2011. The pump is now available as a service item. See later in this thread.

[PhilipA]

My 4.6, Since We did it up a couple of years ago has had low oil pressure at idle, The light comes on sitting at lights etc
Cheers and thanks in Advance !
Jeremy

First question is are you sure your oil pressure is actually low at idle or whether the oil light switch is faulty. Have you checked the pressure with a mechanical gauge???

I have rebuilt an engine with low pressure only to have the light come on in the rebuilt engine. Fix was a switch which is much cheaper.

Regards Philip A

[justinc]

First question is are you sure your oil pressure is actually low at idle or whether the oil light switch is faulty. Have you checked the pressure with a mechanical gauge???

I have rebuilt an engine with low pressure only to have the light come on in the rebuilt engine. Fix was a switch which is much cheaper.

Regards Philip A

As above, try a mechanical gauge first, if the oil pressure really was that low then a fair amount of tappet rattle will be evident. Also, the oil lamp will usually take ages to go out when first starting if oil pump is badly worn, hot or cold.

JC

[Jezzaol]

I have not checked the oil presure with a gauge but its does get a rattle if you leave it go for much more than a couple of mins !

I gues I will check the pressure relief valve?

Cheers
Jeremy

[justinc]

have had a Td5 with this fault, had manufacturing swarf from ally block brace and oil pick up assembly stuck in the relief valve plunger:mad:

Easy fix and caught it before any damage was caused luckily.


JC

[Jezzaol]

Is it a matter of replacing the Relief valve or ??? What should I check or clean ??


have had a Td5 with this fault, had manufacturing swarf from ally block brace and oil pick up assembly stuck in the relief valve plunger:mad:

Easy fix and caught it before any damage was caused luckily.


JC

[justinc]

Hi Jeremy,

Just remove the plunger and carefully inspect the bore for scoring and evidence of the plunger not seating at it's base, IE at rest it should be able to seal off the chamber completely, and the springs actual tension holding the plunger down is what gives you oil pressure. If the spring is weak or broken, the plunger sticking and not seating that will allow oil to bleed off around it and therefore low oil pressure.

If all looks OK, then I would be dropping the timing cover and checking the pump for scoring and wear on the thrust plate.

JC

[p38arover]

Also check the teeth on the gears. They can chew out quite badly.

On reassembly, Loctite the pump screws.

[MoodyBlue]

Ron,
You can replace just the oil pump.

OPK003 Kit O/Pump Repair V8 integ. Cost 58.10 pounds including postage.

Just got one of these from the UK. Qualitypart is the seller on Flea-Bay.


OIL PUMP GEAR KIT FOR ROVER V8 ENGINE FITS VEHICLES WITH AN INTEGRAL OIL PUMP FITTED IN FRONT COVER - SERPENTINE ENGINE CIRCA 1994 ON

*
DEFENDER APPROX 1994 ON
*
DISCOVERY II
*
RANGE ROVER APPROX 1994 ON
*
MORGAN WITH SERPENTINE V8 ENGINE
*
TVR WITH SERPENTINE V8 ENGINE

THESE GEARS ARE SUITABLE FOR THE ENGINES WHICH HAVE THE INTEGRAL OIL PUMP FITTED IN THE FRONT COVER. NORMALY FOUND IN ENGINES FROM 1994 ON.

WE KEEP THE EARLY STYLE KITS AS WELL.

Note there are 3 types of oil pump fitted to the Rover V8 Engines. We carry all three types of replacement gear kits.

www.shop4autoparts.net


No need to go the entire front cover, unless it is chewed out.
On mine the outer ring of the oil pump gear split............

Cheers
Jeff

[p38arover]

Thanks Jeff. I saw the replacement pump on the Island 4x4 website last week and meant to mention it. Same part no., too.

http://www.turnerengineering.co.uk/acatalog/Rotor_Kit.png

[PhilipA]

I read recently somewhere or maybe it was talking to Gary at CLR, that there are two types of timing case gasket, one for camshaft driven pump and one for crankshaft pump, and if you use the wrong one you lose oil pressure because there is not a hole in the gasket where it should be.

Can anyone amplify on this as IMHO it would be pretty hard for a crank driven oil pump to wear out, and otherwise the pressure relief is the only other likely explanation.
Regards Philip A

[Scouse]

I read recently somewhere or maybe it was talking to Gary at CLR, that there are two types of timing case gasket, one for camshaft driven pump and one for crankshaft pump, and if you use the wrong one you lose oil pressure because there is not a hole in the gasket where it should be.

When I first bought my '87, I did a camshaft/lifter change & fitted a later timing cover gasket instead of the correct one. While it appeared to fit OK, the oil pump would not prime no matter what I did due to one hole not sealing the cover correctly.
Lesson learnt :(.

[James445F]

I have 2003 D2 V8 4.0 (130 000km), I was sand driving and oil light came on whilst idling, I continued driving to safer grounds and then came loud ticking noise. I replaced oil and filter,engine stopped ticking and light went off, so I drove home.
The next day I started engine but the light came on at idle again.I decided to pull down engine,removing timing cover to find a CRACKED outer oil pump gear..
I replaced with new the timing cover (includes oil gears,relief valve,pressure sender and seals) New timing gears and chain as they where badly worn,exhaust manifold and flange gaskets all with new genuine parts ,I also replaced oil pickup o'ring, sump gasket and installed a oil pressure gauge, all done by the rover overhaul manual specs and thoroughly cleaned all parts before reassembling.
After all that work, and adding a thicker oil (15-50w instead of recommended thin 5-40w) I started engine to find it was running much smoother and quieter BUT still has zero oil pressure at idle after engine warms up ???? The pressure rises when engine is revved but then rapidly falls back to zero when revs drop??
So I have pulled the engine down again to find more issues!! the upper conrod bearing shells are partially worn down to copper?? I have replaced conrod shells but My guess is that the big end bearings also needs to be replaced whilst the engine is pulled down? but I dont think it is possible to correctly replace the big end bearings without removing the engine as it looks near impossible to achieve the correct torque settings that could result in catastrophic engine failure...
Why is my bottom end in such bad shape? this is a low km well maintained Disco that has had an easy going street life (soccer mum suv) and has never been off road until recently?
Im guessing the top end is also in need of a rebuild?
This low oil pressure problem has already cost me $2000 not including tool costs and thats doing the work myself, I would hate to know what a rover mechanic would have charged me..

[Keithy P38]

Could the low oil pressure have caused issues to bearings, etc?

I'd imagine it wouldn't take long to kill a bearing with no oil getting to it!

Cheers
Keithy

[peter51]

I notice this is an old thread which has been bumped into life by James445F.
BTW James, when you find your issue – make sure you post back the result so we all benefit.

The oil system is an open system. If the resistance to flow on the rocker circuit is lower than the big end circuit then total oil pressure measured at the pump cover will drop considerably.

Oil pressure leakage at the top end is a very common culprit for low oil pressure.

Most people jump straight to the oil pump or the bottom end to solve their low pressure – however the first place to go is the top end.

Remove the rockers and clean them carefully. Note carefully how they are assembled before disassembly – because if you reassemble incorrectly you will have no oil pressure.

Now inspect carefully all parts for cracks and excess wear - Rocker stands, rockers and rocker shaft or rocker shaft plugs. Severe wear or cracks will lower oil pressure considerably.

I can illustrate this by a recent experience. After renewing the stem seals on my P38, I had a helper refit the RH side rockers arms and torque them down. On start I noticed the oil pressure 5 psi lower than normal at at 45psi,( Normal prior to the work was 50), then as soon as the block got to operating temp the oil pressure began to slowly drop until it settled at 10psi – on revving it would go to 25psi. I rechecked oil pressure with another guage to confirm and the hot idle result was the same, however cold idle pressure was now only 40psi.
Before the work, cold idle was 50psi and hot idle was always 30psi. This vehicle has 195,000km on the clock – guage is accurate to plus or minus 2 psi.
On pulling off the rockers we found the RH side forward stand had cracked – my helper had set 38 ft/lbs instead of 38NM on the torque wrench and the forward RH stand had cracked as it expanded. The crack was about 0.5mm wide at the bottom of the stand - obviously more as it got to operating temp.
The oil feed to the rockers is via the front and rear stands.

This clearly illustrates the effect of leakage in the rockers on oil pressure - such al leak at the top end on just one forward rocker stand had a dramatic effect on oil pressure –5 - 10 psi when the oil is at its normal viscosity and a whopping 20psi at its hot viscosity.

A worn rocker set on both LH and RH sides would give the same result. Pressure leakage at the top end is the main culprit for low pressure so go there first. If you don’t fix the top end pressure leakage in an open system,then the bottom end and cam bearings will suffer.

If you repair the rocker sets, and oil pressure has not recovered significantly, then now you should lift the engine and thoroughly investigate – oil pickup screen, pump clearance, bottom end clearances, cam bearing and all galleries
.
As an aside – if the engine has had previous work done and the mechanic used sandpaper or abrasive pads to clean off the gaskets you will probably have severe bearing wear. These abrasive pads contain aluminium oxide which will find its way into the cam and crank bearings. Here they will abrade the bearings in short time. They get past the oil filter either on start when the overpressure relief valve temporarily opens, or is blown around the block when an air tool die grinder is used.
Normal oil film thickness between the bearing journal and the crankshaft is equal to the typical machining clearance - 0.001 inch - but in operation, the crankshaft never spins on centre. As the piston fires the oil layer between the journal and the bearing is squeezed to 0.00004 inches. A typical aluminium oxide particle is much bigger than this and is hammered into the bearing surface whereupon it begins to eat away at the crank

[benji]

I found enough room under there when fixing the car wees (as my 3 y.o. puts it).

I had the airbags up, but if you sit the stands up high enough for the shocks to top out.

I didnt take the crank out, but did clearance checks on the rear two caps. Hard on the arms but achievable.

Did you drive for very long whilst it was ticking? If it were only 30 seconds or so I don't think that would be the cause - but a few minutes under load would do it I imagine.

Your storey is similar to mine in that I rebuilt the oil pump and it still dropped back to almost zero at idle and 24 when cold at 2500. I'd striped the bolt on the pump backing plate, allowing the plate to flex and draw in air. My torque wrench went down to 15ftlb so just guessed the very low figures on the backing plate. I also reused the pickup oring...
After fixing that up (and buying an inch/pound torque wrench) it was all good. I was very suprised how low the torque settings were on the backing plate though! Trusting the locktite I suppose.

One of the tricks to build up pressure to the bottom end in the likes of the Repco motors was to half the oil flow to the top end. Apparently it made a large difference - so increasing the flow would have big consequences too.

On a side note - if you've got the front cover off and the inlet manifold - its not that much more work to take the motor out.

Sent from my GT-I9305T using AULRO mobile app

[James445F]

Wow this is a lot of good info... Cheers . I decided to buy an engine hoist and stand as it seemed near impossible to do the job properly and achieve the correct torque settings a small price to pay considering and pulled out the engine yesterday. I put it on engine stand, removed the crankshaft and the big end shells were in good condition. After inspection of the camshaft area I found that one of the cam bearing shells has slipped out and is resting against camshaft and one of the lifters ? I would never spotted this without pulling crankshaft out or removing top of engine . Now I can easily rebuild the top and bottom of engine without climbing over and under my Disco.
Overall, removing the engine wasn't as hard as I was expecting as It only took me a day on my own no extra hands needed but the correct tools are essential such as good quality air tools, extension sockets, spanners also good advice ..
I will now pull down the top of the engine and inspect also replace cam, lifters and bearings . I'm considering replacing cam with a piper stage 2 rather than a standard one but I'm not sure if I will need to upgrade anything else such as ECU, valve springs etc??
I will be replacing pistons and heads in the near future to complete my rebuild.
Does anyone have any advice regarding this??
Thanx

[James445F]

Also what's the best way to clean the inside of my engine ?

[101RRS]

I will be replacing pistons and heads in the near future to complete my rebuild.


What about putting in top hat liners - given how far the engine will be pulled down I would be putting them in. To me it is too risky to run these engines without top hat liners.

Garry

[peter51]

With the engine out, SERVICE other parts. E,G Overhaul the front prop shaft or do any maintenance that is easier with the engine removed. Take the radiator to the radiator shop to get it rodded. If you can afford it, get a new radiator if it is over 12 years old. Have the starter overhauled because it is extremely hard to remove if it fails whilst in its fitted position.
Look for any issues with wiring looms and connectors – especially corrosion or hardened wiring indicating higher than normal current draw. Spray EML contact cleaner and lubricant on all the injector and sensor connectors in the engine bay at this stage - get it from Jaycar. EML ensures you get low resistance on the connector terminals when you refit.
WARNING: Only use genuine seals for the valley end seals, rocker covers and any o rings and crank oil seals.

Do not use Britpart or ALLmakes valley end seals or rocker gaskets – they become brittle after only 2 years.

Regarding the valley end seals – only use Genuine as Ive tried 3 different aftermarket ones and they all have poor fit compared to genuine - anyway the genuine ones are similar price.

Follow the TSB on RAVE as to sealing the valley.

Valve stem seals- buy a Valve spring removal tool on ebay to do the valve stem seals - Double check the piston is at TDC before releasing the valve collett!! Check valve stem tips, spring resting length, compressed length etc

Change o rings on oil pickup, and both coolant pipes that connect to the lower intake. Go easy refitting as its easy to tear the o rings.

Use locktite on the oil pickup pipe fasteners and the oil pump cover.

You must do a coolant pressure test to ensure you have no coolant leaks before you do the cam break in.
BTW: Do not run the engine with coolant overflow bottle lid off - as the engine warms up coolant will spill out into your fuse box. The dealers did that to my car and caused major problems.

Just make sure you go slowly.

[peter51]

I forgot to add to renew the orings on the injectors - they should be in your VRS kit along with stem seals.

You could also fill the fuel rail (injectors fitted )and leave it pressurised with 40 lbs overnight to check for any leaking injectors. It is easy to make a fitting to do this - 5 minutes. Just orientate the rail with the injectors nozzle down on coloured paper - look for staining in the morning.

If you want to get more technical you can also connect them to 12 v and flow test them with a timer circuit or you can pay to get it done.

Once you do these tests you will be confident about your injectors - although they are extremely reliable parts.

[James445F]

I removed the lower intake manifold to find a large amount of grey sealant has been used on the valley gasket around coolant ports. So much in fact that the rear coolant ports on both heads were almost completely sealed off ? Also found scratching around head ports from past gasket removal. I'm guessing head gaskets or heads were replaced at some stage? Plus there was a large amount of black gritty gunk inside valve covers and top of heads? I'm not sure if this is normal for an engine with 130k and full service history?
After removing rocker assembly and lifters I inspected and found only slight wear to bottom of the lifters and they slid out with little effort..
I then removed camshaft same again only slight wear and the cam bearings were in reasonable condition,
besides the one that had slipped out (2nd shell from rear) which had been resting between cam and lifter and had perfect semi circle cut out of it...
I removed 4 cam bearings but I couldn't get the rear cam bearing out without damage, maybe if I remove the rear engine cap/plug I could get to it but engine stand will obstruct me..
After all this it may not be possible for me to correctly install the new cam bearings as it looks like a special tool is required or they possibly need to be pressed into place?
I have not yet removed the heads or pistons as I was hoping for a easier rebuild..
Does anyone think I should continue with this rebuild ?? As it may be a little out of my league and might cost me more than its worth? 706587065970660
70662

[peter51]

To answer your question whether to resurrect this engine, we need to know the condition of the heads via a leak down test. If each cylinder has a good value then next question would be know whether it used to use water. Look inside each cylinder to. see if any piston tops are steamed clean.

If the leakdown check is good and no tops of the cylinders are steam cleaned then I would encourage you not to give up. Don' t touch the heads. The motor just needs new cam bearings - change front and rear crank seal, crucifix seal on rear cap, and do the other other items from my post and it will run reliably for a long time yet.

BTW, whoever used all that sealant on the coolant galleries was a complete amateur. You can use some on reassembly if you wish but very sparingly . There is a guide to this at CannibalV8 (http://cannibalv8.com/)