Rover V8 blowing oil out of left bank
Discussion
Hoping someone might have an idea here.
On my 3.5 RV8, on the left/nearside bank, at high revs (5500-6000) it seems to expel oil from somewhere that then burns and smokes on the header. The oil comes from the outside edge of the block/heads just about the exhaust ports.
Idea's so far have been rocker cover, dip stick bracket, dip stick.
I've checked and tightened the rocker cover, although it was tight anyhow.
I've done the screws up for the dip stick bracket as they were lose (they screw into the rocker cover).
Dip stick looks ok, but not sure if it should be sealing better.
Only other idea is to change the breather pipe and filter on the other cylinder bank and see if it helps.
But I'm out of ideas really.
On my 3.5 RV8, on the left/nearside bank, at high revs (5500-6000) it seems to expel oil from somewhere that then burns and smokes on the header. The oil comes from the outside edge of the block/heads just about the exhaust ports.
Idea's so far have been rocker cover, dip stick bracket, dip stick.
I've checked and tightened the rocker cover, although it was tight anyhow.
I've done the screws up for the dip stick bracket as they were lose (they screw into the rocker cover).
Dip stick looks ok, but not sure if it should be sealing better.
Only other idea is to change the breather pipe and filter on the other cylinder bank and see if it helps.
But I'm out of ideas really.
What breather system do you have ? In the picture I can see a pipe coming from the breather flame trap but it looks like it is blocked off. If you have the normal breather into the inlet somewhere it may be worth checking that all the pipes and the flame trap are not blocked. The normal way is for air to go in the small (tiny) hole at the rear of the nearest cover (nearest in the picture) down into the block and then out via the vacuum generated from the inlet suction.
In my experience if there is a problem with the breather system it will show itself by by throwing out oil somewhere when the throttle is closed abruptly at high RPM which means that simply revving it doesn’t always cause the symptom.
In my experience if there is a problem with the breather system it will show itself by by throwing out oil somewhere when the throttle is closed abruptly at high RPM which means that simply revving it doesn’t always cause the symptom.
steve-V8s said:
What breather system do you have ? In the picture I can see a pipe coming from the breather flame trap but it looks like it is blocked off. If you have the normal breather into the inlet somewhere it may be worth checking that all the pipes and the flame trap are not blocked. The normal way is for air to go in the small (tiny) hole at the rear of the nearest cover (nearest in the picture) down into the block and then out via the vacuum generated from the inlet suction.
In my experience if there is a problem with the breather system it will show itself by by throwing out oil somewhere when the throttle is closed abruptly at high RPM which means that simply revving it doesn’t always cause the symptom.
That pipe is a little misleading. The pipe off the flame trap goes back up to the inlet manifold, in the pic you can see what was left of a Y section of pipe when I ran twin SU's, the bit cut off is blocked though and air tight. I should really tidy it up.In my experience if there is a problem with the breather system it will show itself by by throwing out oil somewhere when the throttle is closed abruptly at high RPM which means that simply revving it doesn’t always cause the symptom.
It only smokes at WOT and when over 5000rpm (or that's when it becomes noticeable).
300bhp/ton said:
It only smokes at WOT and when over 5000rpm (or that's when it becomes noticeable).
Under those conditions you have zero manifold vacuum (to help pull blowby gasses from the crankcase) and maximum blowby gas production (high load & rpm, so max ring leakage). Any defficieny in you ventilation system will be likely to show up at that point. (and also, exh manifolds will be hot enough to quickly vapourise any leaking oil into smoke that is noticable)Max_Torque said:
Under those conditions you have zero manifold vacuum (to help pull blowby gasses from the crankcase) and maximum blowby gas production (high load & rpm, so max ring leakage). Any defficieny in you ventilation system will be likely to show up at that point. (and also, exh manifolds will be hot enough to quickly vapourise any leaking oil into smoke that is noticable)
Yes it does produce quite a bit of smoke.So what do you think the problem is? Or more specifically what should I address?
300bhp/ton said:
Cheers.
So where do you think the oil is actually coming from though?
Well, I'm not there so I cant see it or what you are doing.So where do you think the oil is actually coming from though?
If it is in the era you suggest, then it would seem the only place can be the rocker cover or gasket
Or is the dipstick tube over on that side on a Rover ? Been years since I looked at one
You can check the dip stick isn't being pushed upwards by crankcase pressure, check the dipstick sleeve is still a snug fit into the block and check the aforementioned gaskets. Lastly and unlikely is the head gasket where the oil passes from the block to the head but that's very unlikely imo. I'd plump for pressure out of the dipstick tube or leaky rocker gaskets. 
). Going to see if I can sort out a catch can and redo the pipe work for the breather too.Catch can ordered last night too.
Think it might be the flame trap, that wasn't great when I cleaned it last and that was ages and ages ago.
Don't think the engine is knacked as it's running stronger than it ever has if anything. Certainly doesn't seem down on power and isn't otherwise burning oil or water either.
Think it might be the flame trap, that wasn't great when I cleaned it last and that was ages and ages ago.
Don't think the engine is knacked as it's running stronger than it ever has if anything. Certainly doesn't seem down on power and isn't otherwise burning oil or water either.
If the flame trap or other parts of the breather system is blocked then the crankcase will pressurise & you will get oil escaping from all sorts of interesting places. Learnt that when I bought my RRC - breather passage in the plenum blocked solid.
Worst case with the Rover V8 is that it could unseat the rear crank seal - that's an engine or gearbox out job.
Worst case with the Rover V8 is that it could unseat the rear crank seal - that's an engine or gearbox out job.
UPDATE:
Ok, O-ring was missing on dipstick so that's been replaced. I didn't get chance to do the rocker cover gaskets, but I did look at the rocker cover flame trap and it was filthy. I've removed the wire wool from it and cleaned it out.
Test drive shows this was the issue as it doesn't smoke as all now.
I've got a catchcan to fit, but need to make a bracket up for it. If I'm running a catch can, do I still need the wire wool in the flame trap?
Ok, O-ring was missing on dipstick so that's been replaced. I didn't get chance to do the rocker cover gaskets, but I did look at the rocker cover flame trap and it was filthy. I've removed the wire wool from it and cleaned it out.
Test drive shows this was the issue as it doesn't smoke as all now.
I've got a catchcan to fit, but need to make a bracket up for it. If I'm running a catch can, do I still need the wire wool in the flame trap?
Purpose of the wire gauze is to extinguish a flame - from a flashback - travelling from the plenum or carbs & prevent it possibly igniting oil vapour in the engine. Which could be interesting! I periodically remove & flush the trap with solvent to remove the crud that builds up - manuals advise to allow it to air dry afterwards and NOT to use compressed air to speed the process up.
When I realised the RR breather trap was blocked I disconnected the hose from the plenum chamber & routed it to go directly to atmosphere as a get-me-home measure. Stopped the leaks immediately.
Normally the crancase ventilation is via the carbs or plenum so oil fumes are drawn back into the engine & burnt.
On the EFi there is a small round foam filter on the top rear of the other rocker cover which is to allow air in.
Don't know whether your catch bottle idea would work but the system as fitted is really so simple why mess with it?
When I realised the RR breather trap was blocked I disconnected the hose from the plenum chamber & routed it to go directly to atmosphere as a get-me-home measure. Stopped the leaks immediately.
Normally the crancase ventilation is via the carbs or plenum so oil fumes are drawn back into the engine & burnt.
On the EFi there is a small round foam filter on the top rear of the other rocker cover which is to allow air in.
Don't know whether your catch bottle idea would work but the system as fitted is really so simple why mess with it?
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