Oil overflow from dipstick tube

[Terry L]

Oil is now gushing from dipstick tube when engine is running. Oil pump must be pushing oil into the sump, maybe through the relief valve - I infer. But what do I know? Any one have knowledge of this? Can I pull the oil pump with out removing the engine? Not sure if there is room because I don't know how long the shaft is. Email me at [email protected] if you can help. Thanks.

[tedtaylor]

could it be a crankcase pressure ventilation problem instead? is the breather tube going to the airbox blocked? do you have another breather tube coming off the top of the valve cover up front? Is your timing retarded too far? have you over filled your oil crankcase? Just a couple simple thoughts come to my mind that may contribute to oil coming from dipstick. I recall seeing other posts on this topic so do a forum search. good luck!

[peterako]

Does sound like excessive back-pressure

Is it gushing or an odd splash?

Do check the breather(s).

Blue smoke from the exhaust??

Is oil coming out anywhere else?

Peter

[PeterK]

How much oil is coming out, is a constant flow of liquid, a pulsing flow or misting ?

IIRC, the bottom of the dipstick tube is above the normal oil level, so excessive back pressure would force oil mist rather than liquid oil (as suggested by the term gushing).

Over filled oil might get splashed (or worse) out of the dip tube.

Can't visualise the oil filter layout and am 200 miles from any manuals, but possibly a blocked filter or failed pressure relief valve in the oil pump would vent back to the sump, perhaps causing excessive misting (& potentially an engine failure due lack of oil pressure through the journals.)

Peter

[Terry L]

Thanks for your responses. Oil was not overfilled and, just to sure, I drained some and the problem persisted. The oil flow was actually pulsing as it came out of the tube. No blue smoke, not aware of any other leaks. Problem arose suddenly. Engine runs fine. Has anyone actually pulled the oil pump on this motor? A mechanic suggested to me that I drop the pan first, and I may do that, to see what I can see.

[stugilmour]

Terry, I pulled & replaced my oil pump with the engine in place, although I think I had to slack off the engine mount and jack it up a bit. Pan was left in place. Note my car is a Plus 2 LHD, so a bit more room than the Elan I think.

HTH

[PeterK]

Oil pick up tube with strainer is bolted from within the sump. Oil pump is attached externally on the side so no need to drop the sump just to change it.
Peter

[oldelanman]

Hi Terry,

Has anyone actually pulled the oil pump on this motor?

It is just possible to get the oil pump out with the engine in situ in the Elan but it's very tight. On a RHD car the steering column and the handbrake cable also run through that area which doesn't help. The only way I could get mine out was to lower and rotate the engine until the pump could just be wriggled out between the upper and lower chassis flanges .... and I also had to remove the carbs (Stromberg) to get enough movement. Not a 5 minute job !

A mechanic suggested to me that I drop the pan first, and I may do that, to see what I can see.

Do you have a removable crossmember ?

[billwill]

Before getting into extensive things like pump removal, do a compression test on the cylinders, you may have combustion gases leaking past your piston rings and pressurising the crankcase.

[Jeff@Jae]

To check the health of the engine do a leak down test to be sure the rings are sealing and you aren't dealing with excessive blow by. Oil level generally wants to be about an 1/8" below full on the dip stick. Check the breather system as noted. Some oil being hurled out of the dipstick tube is normal because of the location and rather feeble breather system. Use a tight fitting spark plug boot ( alonger one is better) and slip it over the dip stick so it seals the opening when the dipstick is inserted. Standard cast pistons use ancient design piston rings that don't live very long and even a good running engine will develop blow by of the rings. Contemporary forged pistons have contemporary rings that have less drag and far better life span. I am about to pull my Twin Cam for that very reason and will use real pistons this time. It runs fantastic but has developed unacceptable blow by.

[Terry L]

Thanks, all. This engine was completely rebuilt (by a pro, not me) less than 2,000 miles ago, with new pistons, etc. Would a back pressure issue arise suddenly as this evidently did? I won't be able to do anything for a few weeks and then we'll see. My cross member is indeed split so dropping the pan to inspect seems possible, albeit messy. Oil pump removal looks much harder and will also require that I drain the radiator and remove the lower radiator hose. Maybe I should concede and drag the car back to the shop (again.)

[kstrutt11]

Have you checked the oil quantity is correct (ie drain and re-fill with the right amount), the dipstick tube can get knocked down to far or the dipstick could be wrong.

kevin

[quaybook]

This really sounds like crank case pressure not the oil pump. Try running the engine with the oil filler cap off, put a lot of rag over and around the filler because oil will splsh out, but if the oil stops coming out of the dipstick the problem is cankcase pressure not the pump. Then check that the breather is clear and if it is, is run a compression test. Fingers crossed for you!

Regards
Vernon

[Terry L]

Thanks to all. Problem solved. There was a blockage in the breather from the block to the back of the air box. There is a tiny screen in there which must have gotten gunked up. I blew it out with air, ran some brake cleaner through, reassembled, and all is better.