V8 valve stem seals

[Quavers]

My 2004 545 failed its mot on a broken spring, track rod end and smoke while idling.
It appears to have the usual valve stem seal trouble - I know of PMP in Nuneaton however I am in Cheshire which is too far to drive without an MOT.

Has anybody had this work done in the Cheshire/Manchester area?

[bimjim]

These guys were recommended to me for the same job, although I never got around to using them (sold the car)...

Fixed Automotive Services

[naturalaspiration]

I guess there isn't much to loose with trying LM Oil Saver? It reduced oil consumption on my mega miles M54 by two thirds - together with LM Ceratec though.

https://www.amazon.com/Liqui-Moly-2020-Motor-Saver...

Increased performance by doing this... https://www.bimmerfest.com/forums/showthread.php?t...

valve stem seals smoking temp fix https://www.bimmerfest.com/forums/showthread.php?t...

If that fails you can always have the valve stem seals replaced.

Please do your own research.

[Quavers]

I used the LM oil saver - it did help.

The car passed it's emissions but failed because it was smoking at idle.

[naturalaspiration]

I'd does take a bit for it all to start to work. I would try changing oil to 10w-60 and adding both the Oil Saver and Ceratec.

Edited by naturalaspiration on Saturday 29th June 05:02

[Quavers]

Another garage is looking at the car next week. It would appear the new MOT regs really are tightening up. If you have a smoky n62 it may not get a certificate from now on.

[mrciarano]

Quavers said:

Another garage is looking at the car next week. It would appear the new MOT regs really are tightening up. If you have a smoky n62 it may not get a certificate from now on.

I might be out of place posting in a BMW forum on Pistonheads but is the smoke that bad on an N62 with bad stem seals? I only ask because I had a (non BMW) car I rebuilt the motor on and took it straight for an MOT in April while it was still burning the assembly oil. Tonnes of blue smoke during the fast idle test but the tester got it through for me without failing it for smoke? Just saying if the regs haven't changed since April, might be time to ask a more lenient garage for a test?

[Quavers]

I can drive the car at motorway speeds and it does'nt smoke. My wife followed me the 7 miles to test centre - she saw no smoke. I drove it home from the test centre with no smoke. It only smokes when idling on a hot engine - vacuum is pulling the oil down the valve guides.

Car has only done 87k. I need a valid MOT to get it to the specialist. Tester annoyed me by saying it had had a hard life - I asked him why it had had a hard life - he replied " because it's smoking."

[naturalaspiration]

The reason for seal hardening is excessive engine temperature - rubber does not like it- I understand there are thermostats on the market that can keep the N62 temperature down to 90 or vs insane 110+ figures courtesy of BMWs OE setup. The problem with high coolant temperature is that it also makes oil very hot and hence thin - easier to be pulled out by the vacuum at idle. Hopefully a combination of a colder thermostat, thicker oil, oil saver and ceratec may just do the trick.

[eliot]

Quavers said:

I can drive the car at motorway speeds and it does'nt smoke. My wife followed me the 7 miles to test centre - she saw no smoke. I drove it home from the test centre with no smoke. It only smokes when idling on a hot engine - vacuum is pulling the oil down the valve guides.

Car has only done 87k. I need a valid MOT to get it to the specialist. Tester annoyed me by saying it had had a hard life - I asked him why it had had a hard life - he replied " because it's smoking."

Smoking at idle is classic valve stem seals. I bought the tool and did it myself, but it's not a job for the novice or impatient. You can rent the tool via a fb group. There are a couple of places that specialise in doing them for about a grand.
To add; They usually last over 100k - hope yours isnt clocked.

[Quavers]

eliot said:

Smoking at idle is classic valve stem seals. I bought the tool and did it myself, but it's not a job for the novice or impatient. You can rent the tool via a fb group. There are a couple of places that specialise in doing them for about a grand.
To add; They usually last over 100k - hope yours isnt clocked.

It's not clocked - tbh I have heard of them failing at 70k.

[gf15]

I had mine done at a specialist close to Manchester airport at 140k miles. Now on 192k and uses no oil. I will dig the info out in the morning.
It cost £1.5k which included the cam cover gaskets. The engine was dropped so the valve seals could be changed out.

[oakdale]

Wynn's super charge additive is very effective with stem seal smoke.

[eliot]

oakdale said:

Wynn's super charge additive is very effective with stem seal smoke.

If it works i would hate to think what it does to the engine. The exhaust side stem seals on my 750 were like bakelite when i changed them. No additive is going to soften them.

[Quavers]

I tried another garage. They felt the smoke was'nt enough of an issue to fail. They recommend using additive and a heavier grade oil. Car now has a ticket.

[eliot]

Quavers said:

I tried another garage. They felt the smoke was'nt enough of an issue to fail. They recommend using additive and a heavier grade oil. Car now has a ticket.

Be glad you have a ticket. Plan to get it repaired in the next 12m or so. Having personally changed the seals, I can tell you they go rock hard and brittle - I can't see how additives or thicker oil is going to make any difference.

Existing thread on the subject:
https://www.pistonheads.com/gassing/topic.asp?h=0&...

[Andy665]

Must be my OCD kicking in as I would be arranging to have the valve stem seals done asap

[Quavers]

eliot said:

Be glad you have a ticket. Plan to get it repaired in the next 12m or so. Having personally changed the seals, I can tell you they go rock hard and brittle - I can't see how additives or thicker oil is going to make any difference.

Existing thread on the subject:
https://www.pistonheads.com/gassing/topic.asp?h=0&...

The garage that passed the car said the petrol bmw's have a tendancy to smoke and that they use an additive during a service. I will get the seals replaced later in the year ( a holiday is in the way). I don't mind spending £1k on the car as it is low mileage and in good condition.

I am surprised at the number of "specialists" that would'nt do the job - as cars evolve I am not sure many will survive on servicing and minor repairs alone - car will have to go to PMP which is not on my doorstep.

[ckl139]

How did you get on with this and specifically PMP?

Good result?

Are their price fixed?

[Quavers]

PMP did the job for the price quoted with no dramas or sucking through teeth.

My car no longer smokes and runs much better.