I used the holiday to take care of several outstanding maintenance items on my 1997 XK8 coupe. I upgraded the secondary timing chain tensioners (using the "zip tie" method), replaced the valve cover gaskets, replaced old and brittle ignition wires and connectors, and cleaned the throttle body, MAFS and part-load breather.

I started her up and have no obvious leaks, ticks, misfires, or CEL. Sounds like everything went according to plan, but after idling and getting up to temperature, I have white smoke, apparently leaking from between the valve covers and heads!

My first thought was that I may not have tightened the valve covers enough and that oil was seeping and hitting the exhaust manifolds, even though I followed the correct "inside to outside" bolt tightening sequence and used a torque wrench set at 11 nm. However, the smoke doesn't seem to be coming from the the top of the exhaust, but from the seams between the valve covers and heads. I checked the torque just to be sure, and everything is correct.

Any help is appreciated. I have a few ideas, but would like your expertise:

• Is it possible there is just some residual oil on the gaskets or mating surfaces that has to burn off?
• When I removed the valve covers, the oil separator plates fell off. I reattached them with black RTV sealant. It's rated for 500* F, but could it be burning?
• I used dielectric grease when I reattached each spark plug boot and electrical connector. Could this be burning off?
• I used the correct, Jaguar OEM gaskets (not the Fel-Pros). The set came with the spark plug gaskets, but not the bolt seals, so I reused these. It's possible there is some oil seeping there, but again, the smoke seems to be coming from inside the covers.
• Finally, is there something I could have screwed up replacing the tensioners? I was very careful here, following the instructions from EZDriver on this forum and torquing the tensioners and cam caps to 14 and 11 nm respectively.

Thanks in advance for your help!

Benjamin

 

My first thought is that the part load breather is plugged and you are seeing cylinder blow by. You said the baffles fell out. They are actually demisters for the part load breather and the full load breather.
Try removing the part load breather hose and check to see if there is any air flow from the crankcase pressure coming out of the tube fitting. You could also try removing the oil dipstick and see if you get the white smoke coming out there. If you do the breathers are definetely plugged off.

 

Thanks, Vern!

Yet another example of the simplest solution being the best solution. Though I cleaned the part load breather, I must have been a bit too gentle and just dislodged the gunk, causing a worse blockage than there was in the first place. This time, I gave it a good clean, and happy to report no smoke after idling 20 minutes.

Now, if you can just help me find that 8 mm socket I dropped in the engine bay yesterday...

 

I have an 8mm stuck between the right fender and the wheel arch cover. Just waiting for a reason to tear off the wheel arch cover and get it out. LOL
Glad to hear your problem wasn't serious. Good job on the tensioners.