blue smoke on overrun-vr6

[peanut 0]

right, any help here would be greatly appreciated.

Working on a rado vr at the moment, its had the head gasket replaced, Whilst it was being done it was found to have no thermostat. According to the owner this had been removed 2yrs previous due to overheating problems (which will explain why it always ran cold). The gasket didnt fail completely but had started to go and was losing a bit of water. Used a little bit of oil but nothing major, circa 1ltr per 1000miles which iirc is acceptable on a 160k engine which this is. Head was checked for trueness, all was fine and no cracks. H/G replaced as was new thermostat.

Since this was done its started smoking quite heavily on overrun, most noticeable when changing donw through the gears and slowing down (like coming upto a roundabout or junction) Its using a fair bit of oil, the smoke out the back is mostly blue with a hint of white.

Did a compression test and came up with the following

no1 cyl- 160spi

no2 cyl- 180psi

no3 cyl- 160psi

no4 cyl- 180psi

no5 cyl- 160psi

no6 cyl- 165psi

According to autodata this seems to be within tolerance.

 

Any ideas what this could be? initial thoughts were that it could be valve stem oil seals, but now leaning more towards it being the rings possibly due to it now working at normal operating temp and the oil being sucked up past the rings. When the plugs were romoved the rear 3 were slightly oily and sooted up but the front ones were nice and clean.

Can the valve stem oil seals be replaced with the head still on? Am i right in thinking there is a special tool for this?

Any opinions would be greatly appreciated

Gav

[Roger Blassberg 0]

You can get an adaptor for a compressed air line which screws into the plug hole and holds up the valves whilst you take off the springs, collets etc. So you can replace the stem seals in situ. I would certainly do this before stripping the bottom end.

 

Best wishes

 

RB

[peanut 0]

thanks for that, itll be a replacement low mileage bottom end rather than a rebuild though.

Opinion on wether it might be stem seals or rings from the info ive given?

Thanks

[JIMMI 0]

Id say valve stem seals as well mate, they are super cheap as well so i'd give them a whirl,

 

Jimmi.........

[peanut 0]

ok, might be an option. Does anyone know where i can get the tool from? or can i borrow someones? quite happy to put down a deposit if necessary

Gav

[dr_mat 0]

You need to do a leak down test to figure out if the rings are good or not. Sounds pretty ill though. 1ltr oil per 1k miles is a lot, despite what the book says .. I might be starting to save up for a rebuild in your shoes. :(

[double-6s 0]

It does sound a tad fatal possibly. Very similar symptoms to mine, and when that was taken apart it was fooked :(

 

Good luck though, it may be something way less expensive :)

[Kevin Bacon 5]

Yeah sounds like because it's now at normal operating temp, the oil is thinner and escaping past the worn stem seals and / or rings as you say.

 

Was there any bore scratching or excessive wear on the thrust sides when you took the head off?

 

160k is a lot of a 2.9..... just sounds like it needs a top end rebuild.