97 740i engine trouble - United Bimmer Community

**sandersnsandy** · 03-09-2008, 07:27 PM

Im new to this site so I hope im in the right place to ask---My problem started with a whiring noise sounding something like a tension pully bearing.Put diagnostic and got back codes P1186,P1187,PO300,PO301,PO302,PO305 an PO306 I Then replaced o2 sensors (pre cat) and cleared codes.No new codes have come back. Whiring noise still there and smoking like a freight train.Smoke smells like burning plastic/rubber.I removed oil filler cap only to find its pulling a very strong vacume.With cap off whiring noise stops but smokes just as bad.It only has 94,000 on the clock and I havent had any trouble before now.Dont know where to start. Any help would be very much appreciated,

witeshark · 03-09-2008, 08:14 PM

I think one of the accessories may be stuck, and the smoke may from the belt (which will soon break)

**sandersnsandy** · 03-10-2008, 08:26 PM

Quote:

Originally Posted by witeshark

I think one of the accessories may be stuck, and the smoke may from the belt (which will soon break)

I wish it was that easy. It Has a serpintine belt and seems to be running smothly along the pulleys.
thanks anyway

**Numark318i** · 03-10-2008, 11:23 PM

hmm. how about the waterpump? Tat might be the whinning noise?

**Antiburn** · 03-11-2008, 08:26 PM

Its your pcv valve which is causing that train whistle noise, also the reason your blowing smoke, all that oil vapor is getting burnt. Dealership will change you 6+ hrs labor to remove intake and repalce pcv valve. If you want to do it yourself a 97 v8 has drive by cable, so theres no unpluging the throttel, theres alot of cables and hoses that you have to remove.

Parts might run you about 100$. While your intake is off its a good time to replace your valley pan and water pump, since they both tend to leak and fail down the road.

Also with all those codes im sure they are all missfire faults or fuel trim faults which is unmetered air leaks. Once the pcv is replaced clear them and they shouldnt come back unless something else is also wrong. With all the oil your blowing I know its cloging up your catalitic converters causing premature failure, and they go for $1700 per cat.

**sandersnsandy** · 03-11-2008, 11:02 PM

Quote:

Originally Posted by Numark318i

hmm. how about the waterpump? Tat might be the whinning noise?

Just replaced water pump last summer and it seems OK thanks for the imput Will intertain any idea.

**sandersnsandy** · 03-11-2008, 11:12 PM

Quote:

Originally Posted by Antiburn

Its your pcv valve which is causing that train whistle noise, also the reason your blowing smoke, all that oil vapor is getting burnt. Dealership will change you 6+ hrs labor to remove intake and repalce pcv valve. If you want to do it yourself a 97 v8 has drive by cable, so theres no unpluging the throttel, theres alot of cables and hoses that you have to remove.

Parts might run you about 100$. While your intake is off its a good time to replace your valley pan and water pump, since they both tend to leak and fail down the road.

Also with all those codes im sure they are all missfire faults or fuel trim faults which is unmetered air leaks. Once the pcv is replaced clear them and they shouldnt come back unless something else is also wrong. With all the oil your blowing I know its cloging up your catalitic converters causing premature failure, and they go for $1700 per cat.

codes were for the 02 sensors so that part is ok. And I think your on the right track with the pcv valve. Icouldnt think of anything that would put that much vacume in the crankcase. I will leave a note after I replace the pcv valve. Thanks for the imput!!

**540i Quad pipe** · 05-12-2008, 03:58 PM

I take it you got your problem sorted out? Sounds identical to a problem I had a couple of weeks back with my 97 540i - same engine. Same issue also with taking off the oil cap or removing the dipstick - noise and smoke stopped. Oil Separation Valve at the rear of the manifold nearest the bulkhead was the issue. The 'whining' noise was coming from deep down in the engine somewhere (who knows what...) and the smoke was serious. Not too difficult a fix thanks to some threads I found on here. I have a link to photos and procedure for replacing without removing the manifold if you're still stuck for a fix. Costs about £75 for the partand a few hours with the right tools.