Hi, all

I have a '97 XK8 whose timing chain cover might not have been torqued down properly.

When looking for the torque spec I came across this image at blackonyx where it calls for 11-13 Nm torqued in a sort of criss cross pattern vaguely from bottom to top.

The page is about the X308, though. Can someone confirm that it would also be correct for an XK8 with a 4.0L NA engine?

The image: http://jaguar.blackonyx.net/Images/x...imingcover.jpg
The article: Tmingi chain and tensioner replacement

Thanks!

 

The image appears to come from JTIS, and both motors are AJ26 so you're pretty safe to follow that pattern.

Are you getting oil seep/leakage?

 

Yep, I'm losing a significant amount of oil, and it looks like it's coming from that seam. It's kind of all over the place on the front of the engine, and there are small pools of it collecting on crossmembers bellow the front of the engine.

I've had the car half a year now, and it's always leaked oil. At first it was leaking onto the exhaust manifolds, and then I realized the cam cover bolts were way loose. When I torqued them to spec it instantly cured the leaks from the top of the engine. I also found that one spark plug cover was put on backwards, so someone hadn't gotten the covers reinstalled quite right.

The oil loss was tolerable for a while, but it's getting worse lately, so it's time to track down the rest.

I have, by the way, checked the breather tubes, thanks to recommendations on this forum. They were fine.

 

As bolts weren't properly torqued, that same someone probably didn't use NEW gaskets on the cam covers either.

The plastic covers are easily cracked at the bolt holes if over tightened. The low recommended torque is sufficient to lightly crush the rubber gasket and form an oil tight seal. However, after repeated heat cycles, a previously used gasket will not reform/deform again to seal efficiently.

Graham

 

+1
At least the someone wasn't minded to torque up with a breaker bar so the plastic has survived intact

Wipe all the oil off, check the torque figures and see how you go. Another possibility is a leaky crank pulley seal as that can cause oil to be flung oil around.

Good luck!

 

Yeah, those are my thoughts exactly. I really hope it's not a crank pulley seal and that torquing the bolts will be a low hanging fruit of a solution.

I don't have time or skill for changing the crank pulley seal at the moment, so based on some other hints in the forums I think I'd try Lucas Oil Stop Leak next, just in case it could buy me some months.

In the last couple of weeks it's gotten to the point that I use a quart of oil for every hour of interstate driving to keep it between the holes on the dipstick. I don't know if it's gotten worse because I switched to full synthetic oil or because whatever seal is wearing out faster, but I figure that really points to the crank pulley seal because the timing cover gasket wouldn't get worse over time like that.

Anyway, I just wanted to write down my thoughts in case it helps anyone else somehow. I'll report back.

 

Sorry - I read timing cover and thought cam cover. Disregard my post #4

However, I've never been impressed with products claiming to stop oil or water leaks as their efficacy is at best marginal and at worst imagined.

That is a MASSIVE amount of oil to be using. It's about 12% of the capacity. The danger is that the seal could fail completely and rapidly dump oil to the point where pressure is lost with the risk of bearing damage.

Graham

 

IMO those 'stop leak' products are about as much use as this:
Lucas Replacement Smoke Kit

I'm not sure how they differentiate between holes that need to be blocked and those that don't (OK it may be contact with air) but I'd give them a wide berth.

Another thought:- does your car have an engine oil cooler? There are many posts on these hoses leaking. Not as common this side of the pond as we don't get the heat but - yes - that is one doozie of a leak.

@Graham? - your post #4 was in-context.

 

As an update, I spent some time poking around with the hood in the service position today, and I'm seeing oil pooling in the nook next to the alternator/idler. I also see a tiny pool of oil in the nook next to the water pump.

The instructions from blackonyx talk about putting sealant on the gasket at a couple of locations near the alternator, so now I'm wondering if the timing cover was installed without sealing those locations, and if lack of sealant could cause the size leak I'm seeing.

I don't have an oil cooler BUT I do see oil pooling in the depression in the sump area where I think oil cooler lines would be if I had one. I can't get eyes in there, but I wonder if there might be a leaking plug that plugs ports where the oil cooler would go.

It's funny, though: you guys point out that it is quite a bit of oil loss, and I'm reminded of the boiling a frog slowly story. The rate of oil loss increased so slowly that I suppose I didn't think much of it until I needed quite a lot for a long trip last weekend.