Was travelling along the A46 dual carriageway and got the chance to power away and a large plume of smoke came out the back end, 'Oh, dear!' I thought, 'I may have blown a turbo!' So kept the speed down, and didn't notice any problems with the engine in any way, so when i got to my destination I left her running and checked all round her. No oil leaks, no smell of burning oil from either zorst, but there was smoke coming from underneath her!

Anyway, that was the other week, I've had her up on ramps since then and, although we could see signs of oil, couldn't see anywhere that it might be coming from! But it is defo landing on the Cats, hence the burning.

Did the same journey this weekend and did the same again, big plume of smoke again, and then the smoke from underneath, which is defo a burnt oil smell!

Right, I've checked the oil levels, and the engine is fine, but the auto-box is high! But it must have been high since it was re-built last year.

So, is there any way that some of the auto-box oil is being frown out of the box under high load? (No signs of it coming out of the dipstick) I've checked out the engine as much as I can, and there isn't any real important signs of oil anywhere there.

 

All help appreciated. :bow:

Same thing happens to mine.

Went to Thetford about a month ago and had exactly same proble.Blue smoke coming from oil on cats.Not noticeable when driving along only notice a whisp of smoke in the air when i come to a stop.

Then it didnt do it since then on way to todays meet got a slight return of the smoke again once when i stopped at Wymondham to meet vai0 before going on to Diss

Its bugging me because the oil levels dont seem to be dropping.

not a good thing to have to much oil/fluid in the autobox m8

can do as much damage as not enough

luckily you won't have used yours much will you?

but i would deffo get it sorted asap;)

 

lol not a great help for your oil leak/smoke i know

also you SHOULD be able to tell the difference in burnt oil and auto fluid

so hopefully be able to suss which

usually this is a sign that the RMS (rear main crank seal) is on it's way out.

 

the effect gets a lot worse when crankcase pressure gets higher then normal (eg. due to an engine oil overfill or clogged/malfunctioning PCV valves)

 

look for signs/drips of oil on the lowest point of the belhousing , where the gearbox meets the engine (there's a small hole there to prevent oil build up in the bellhousing.)

had mains seal done on engine rebuild-interesting

usually this is a sign that the RMS (rear main crank seal) is on it's way out.

 

the effect gets a lot worse when crankcase pressure gets higher then normal (eg. due to an engine oil overfill or clogged/malfunctioning PCV valves)

 

look for signs/drips of oil on the lowest point of the belhousing , where the gearbox meets the engine (there's a small hole there to prevent oil build up in the bellhousing.)

Right, thanks for that. That sounds like a damm good contender, as I have noticed some oil deposits on the rear of the engine. Is it possible to replace this seal in-situ?

>> Is it possible to replace this seal in-situ?

 

not really...gearbox needs to be dropped

>> Is it possible to replace this seal in-situ?

 

not really...gearbox needs to be dropped

Thanks for that info, I'll look more in to it :bow: :duffer:

if it's the rear main oil will be dripping from bottom of bellhousing ! Is urs wet ?

if it's the rear main oil will be dripping from bottom of bellhousing ! Is urs wet ?

It's not dripping, but then this seems only to be happening when I'm powering the car, not under normal driving. When she was up on the ramps, there was oil in various places, but nothing was conclusive as to where it was from, can't remember if there was oil on the bottom of the bell housing or not, will get down and take a look tomorrow.

Could be rear rocker cover leak, will work its way down round bell housing and drip on cats too

update on mine-had a look and cant see any leaking around bellhousing

 

Ive i give the car some hard driving and come to a rest it will smoke but after i stop for say 5-10mins on idle it stops would this indicate it could be the a gearbox seal as the little smoke that does emerge when left for the 5-10 mins seems to appear at roughly where the rear of the gearbox is-is there a gearbox/prop seal that could go?

 

 

If it was a mians seal wouldnt it leak all the time-even at idle?

 

its going into a garage tommorow anyway but just trying to bounce some ideas off peeps

There is an oil seal on the box inside the bell housing where the torque converter goes into the box the end of the converter locks into the gearbox pump. You say the engine has been out recently? Its possible that the torque converter was not unbolted from the flexi plate (fly wheel in a manual) when the engine was pulled, not unbolting the converter will result in it being pulled out with the engine, if this has happened the converter would have to be put back prior to engine being put back other wise damage to the pump may occure if its not located in the pump properly, its possible the shaft of the converter may have nipped the seal and thats why it could be leaking? Not saying this is what happened but possible.

 

To check if transmission fluid is leaking from this seal, remove the starter you should be able to get your fingers behind the flexi plate and feel the converter and with bit of luck if any fluid is on it.

 

If it is this seal or rear crank seal box will have to come out but dont forget to unbolt converter from flexi plate first by undoing the bolts holding it on through the starter hole turn the engine by hand untill each bolt can be seen. Good luck

There's also a seal at the end of the gearbox (where the propshaft enters the gearbox)

On manuals this is also a common leak, but not so much on autos

 

if it leaks there on an auto, it's usually caused by an overfilled gearbox. (ATF)

update on mine-had a look and cant see any leaking around bellhousing

 

Ive i give the car some hard driving and come to a rest it will smoke but after i stop for say 5-10mins on idle it stops would this indicate it could be the a gearbox seal as the little smoke that does emerge when left for the 5-10 mins seems to appear at roughly where the rear of the gearbox is-is there a gearbox/prop seal that could go?

 

 

If it was a mians seal wouldnt it leak all the time-even at idle?

 

its going into a garage tommorow anyway but just trying to bounce some ideas off peeps

 

Hey mate

I have EXACTLY the same problem as you. Could you keep me informed with what the garage say please. Its rather embarracing when you pull up at the lights and loads of smoke emerges for under the Zed! :headvswal

Hey mate

I have EXACTLY the same problem as you. Could you keep me informed with what the garage say please. Its rather embarracing when you pull up at the lights and loads of smoke emerges for under the Zed! :headvswal

 

 

Will do mate.

As has been mentioned, the main seal sounds like it has gone. Gearbox/ clutch/flywheel off for that one. It's old and hard but you may have a slight build up of crank case pressure to make it finally go...replace PCVs, if that doesn't solve it, get the compression tested...as a matter of course. As if it's something more terminal and you replace the main seal, then something big has got to come out again...worst case scenario etc....so maybe check the compression anyway before doing anything other than PCVs/hoses.

did u check the oil level in the box correctly? with the box warm, engine running and in Neutral? it always looks high otherwise

just a thought.

 

Fraser

did u check the oil level in the box correctly? with the box warm, engine running and in Neutral? it always looks high otherwise

just a thought.

 

Fraser

 

Oil in gearbox did look high when warm and has dropped recently.

 

I will find out soon though :rolleyes:

As has been mentioned, the main seal sounds like it has gone. Gearbox/ clutch/flywheel off for that one. It's old and hard but you may have a slight build up of crank case pressure to make it finally go...replace PCVs, if that doesn't solve it, get the compression tested...as a matter of course. As if it's something more terminal and you replace the main seal, then something big has got to come out again...worst case scenario etc....so maybe check the compression anyway before doing anything other than PCVs/hoses.

 

Changed the pcvs the other day...I hope it the gearbox or something silly.

Do a compression test anyway, just to make sure. Doesn't take long and could save you the cost of dropping the gearbox if the engine needs attention as the lot will have to be dropped anyway.

... Its rather embarracing when you pull up at the lights and loads of smoke emerges for under the Zed! :headvswal

LOL, I know what you mean :D

 

Mines still doing this, autobox level still the same, but starting to notice a drop in the engine oil level, so looks very much like the crank seal. Will probably do the PCV's as well anyway.... but (and this is where I look a bit stupid) can anyone tell me where they are? Couldn't find a reference in the manual (probably just didn't look very hard :rolleyes: )

They are towards the back of the plenum either side underneath the pain intakes.

...it's the hoses that can be a biatch to do.

where are the other pipes located?

Any diagrams?

There are 5 hoses, 2 per valve. 1 from valve to hard pipe, then one from hard pipe to central hardpipe..both sides. They route round the back and join up with a central central hose which is at the back of the engine in the middle.