my 4.8 sounds like a diesel..

[jlam86]

Hey fellas,

My car is making a strange noise lately. It sounds exactly like a diesel from back in the day. louder tack tack tack sounds. Car runs smooth without any CEL or anything. You can't hear it from the inside of the cabin. Friend who is a mechanic said it is either the valves or the timing chain guide. Anyone else have a similar issue? diy?

also, i think my serpentine belt is chirping on cold starts. Once it warms up, it goes away.

lastly, my driver side valve cover gasket is starting to weep.

sigh...this car is getting to be quite troublesome. NOt digging it. she has 75000kms and is regularly serviced. anybody know of any good diy's for my last two issues? i've found info for the inline 6 but not the 8 cylinders.

Thanks in advance

[seattle]

Your friend is probably right. Due to gasked leaking, I am leaning towards valves. They usually start knocking due to lubrication or timing belt issues (i.e. open close at wrong time).

[jlam86]

So if I fix the leak, should this maintain the lubrication of the valves and timing chain?

or do I have to make valve adjustments etc etc?

[JCL]

Originally Posted by jlam86

So if I fix the leak, should this maintain the lubrication of the valves and timing chain?

or do I have to make valve adjustments etc etc?

No, a valve cover gasket leak has no relationship to an engine noise, unless you leaked so much oil that you ran it dry.

You have to find the source of the noise. The leaking gasket is just something to fix while you are in there.

[jlam86]

i went under the car today and noticed quite a bit of oil residue on the driver side of the vehicle. I toppped up the oil for the time being while I order the valve cover gasket parts in. It did suppress the diesel sound quite a bit but it's still there when you listen for it specifically. the dip stick was between the 3/4 and full mark.

I can't seem to find a service manual for this car. does anyone have it? I am more than happy to pay for this thing too. I have had nothing but problems with this car. CPO is useless! they make it sound so nice when they sell you the car but don't cover bleep all!

[jlam86]

So i brought the vehicle in to bmw and they had a quick listen to the vehicle. The result of the noise was a failed water pump which they are covering under the CPO warranty.

During the diagnosis of the vehicle, they found that the two upper timing cover gaskets need to be replaced (my leaky oil issue) and gave me a quote of $2931.09.

They also found my vacuum pump was leaky and that would cost $646.50

My grand total with Taxes and shop supplies comes out to be $4104.85..

Needless to say, time to whip out the tools. Man am I ever considering to sell this thing now. 1 year of sure painful ownership... probably first and last bmw

[seattle]

I thought valve gaskets/oil leaks are covered under CPO (and extended warranty). You might want to research that topic before whipping out $$$ or doing it yourself.

A quick search on the interwebs turns out conflicting stories - some get it covered, some dont.

[jlam86]

I read what is covered from cover to cover 3x.

seals and gaskets are only covered if they require replacing while replacing a faulty part on the car. water pump is on CPO but not vacuum pump. Its like they know what are prone to failure and don't honor it lolm

[Mackskibum]

If the 4.8 is put together the same way as the 4.4, the timing cover gaskets are a 14 hour flat rate IIRC. I did this on my 2000 4.4- I damaged it when replacing the valve cover gaskets. There was a service tool required for the job- the bottom of the timing cover seals part of the oil pan. The bolt holes in the timing cover are slightly over-sized to allow pressure to be applied to the oil pan gasket. The tool bolts in place with the valve cover removed and puts the required pressure on the timing cover- you then tighten the cover bolts to maintain the tension. Clever design, but a RPIA.

Good luck with the DIY.

[jlam86]

what did you damage when doing the valve cover gasket? the vacuum pump?

isn't there an o ring between the block and the vacuum pump to keep the oil in? why else would the vacuum pump be leaking oil?