Smoke from engine compartment - any ideas?

Gjm91 · Post by **Gjm91** » Sun Dec 02, 2018 7:27 pm

Hi all - when I started my z4 ( 2.0) this morning I noticed a burning type smell and small amount of smoke coming from the engine bay - the area near the heat sheild - oily rather than plastic. The car had been sat over the weekend and I noticed it from cold almost as soon as I started her up. The smell/smoke lasted about 30seconds then stopped - i turned off the engine and started up again and no repeat. - checked oil and no issue nice and clear and electric gauge said level spot on, checked coolant and shows level fine- drove car to Mum and Dads about 45 mins each way and no repeat of issue - temp gauge fine and drove well without any problems no warning lights. No signs of any burnt wires/cables in engine bay- no sign of any leaks oil or otherwise- read a thread about oil leaks associated with the valve cover gasket but noticed the smell from cold so would not have thought that exhaust manifold would have been hot enough to burn anything off- just started her up again after being sat outside all afternoon and no issues- anyone got any ideas/experienced similar from cold? - I heard that the smog pump can also leak but cant see any signs of any oil etc . Could it be some crud from the road burning off?

andyf1140 · Post by **andyf1140** » Sun Dec 02, 2018 8:17 pm

When I had this it was oil dripping on to the cat from the vacuum pump on the back of the head.

Trav · Post by **Trav** » Sun Dec 02, 2018 8:26 pm

Zeds dead... Sorry couldn't resist. I had something similar once (not in a Z) and found the culprit eventually to be a bit of plastic bag that got sucked up off the road. Just where the exhaust was still hot enough. Went away pretty quick though.

Number5 · Post by **Number5** » Sun Dec 02, 2018 8:33 pm

It sounds like you may need to replace the rocker cover gasket.. It can develop a leak at the rear and then drips occasionslly on to the manifold. Gasket is about £30 from ECP and it takes about 90 mins to do.. There are videos on you tube .

Alternatively and sspilt oil around the filler cap will travel under the cover to the back and have the same effect.. Have you topped up the oil recently and possibly spilt any ?

Gjm91 · Post by **Gjm91** » Sun Dec 02, 2018 8:50 pm

andyf1140 wrote: ↑Sun Dec 02, 2018 8:17 pm When I had this it was oil dripping on to the cat from the vacuum pump on the back of the head.

Cheers andyf1140 - where abouts is the vacuum pump so I can check to see if there is any signs of oil

Gjm91 · Post by **Gjm91** » Sun Dec 02, 2018 8:57 pm

Number5 wrote: ↑Sun Dec 02, 2018 8:33 pm It sounds like you may need to replace the rocker cover gasket.. It can develop a leak at the rear and then drips occasionslly on to the manifold. Gasket is about £30 from ECP and it takes about 90 mins to do.. There are videos on you tube .

Alternatively and sspilt oil around the filler cap will travel under the cover to the back and have the same effect..
Have you topped up the oil recently and possibly spilt any ?

Cheers Number 5 - gonna start checking for any oil around the valve cover after its left overnight - had a service about a month ago but would have thought any spilt oil would have burnt off by now

andyf1140 · Post by **andyf1140** » Sun Dec 02, 2018 10:17 pm

Gjm91 wrote: ↑Sun Dec 02, 2018 8:50 pm
andyf1140 wrote: ↑Sun Dec 02, 2018 8:17 pm When I had this it was oil dripping on to the cat from the vacuum pump on the back of the head.
Cheers andyf1140 - where abouts is the vacuum pump so I can check to see if there is any signs of oil

Its at the back of the head on the left.

Gjm91 · Post by **Gjm91** » Sat Dec 08, 2018 3:03 pm

andyf1140 wrote: ↑Sun Dec 02, 2018 10:17 pm
Gjm91 wrote: ↑Sun Dec 02, 2018 8:50 pm
andyf1140 wrote: ↑Sun Dec 02, 2018 8:17 pm When I had this it was oil dripping on to the cat from the vacuum pump on the back of the head.
Cheers andyf1140 - where abouts is the vacuum pump so I can check to see if there is any signs of oil
Its at the back of the head on the left.

Hi Andyf1140 - thanks - turns out your sugestion was spot on - vacuum pump leaking - did you fix yourself or garage.? What sort of price is the repair.

Cheers

weegeoff · Post by **weegeoff** » Sat Dec 08, 2018 6:15 pm

I did mine you get the gasket from BMW it is a little round thing. Make sure you have the right thingy for the screw head or you could strip it,
and you may have to undo the heat shield or bend it a little to get your hand in.

eleflo · Post by **eleflo** » Sat Dec 08, 2018 7:00 pm

I had the same, replaced the gasket and used a good sealant before putting back together, it did last a while but eventually I replace the pump. They do come up on Ebay.

andyf1140 · Post by **andyf1140** » Sun Dec 09, 2018 2:04 am

It might be a sign that the ccv is bunged up a mechanic friend said that when it's not breathing properly it sucks the seal an wh8ch makes it leak

Gjm91 · Post by **Gjm91** » Sun Dec 09, 2018 8:40 pm

Cheers all - gonna get her booked into local indie as need rear pads and brake fluid also- hope its just the seal on the vacuum pump- been checking oil level and no change and no blue smoke from exhaust - also still has slight vacuum on the oil filler so hope the ccv is functioning ok -

andyf1140 · Post by **andyf1140** » Mon Dec 10, 2018 1:03 am

Can you see if it's been replaced in the service history? Mine had done 97000 and hadn't been changed and the only symptoms were oil leaks and a rough idle. As soon as it was changed the idle smoothed out and the acceleration through the lower rev range was smoother as well. Only cost £120 for the part and an hours labor.

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