Hello guys!

New tensioners where installed yesterday, and it did help a lot.
No rattling can be heard, the engine runs smoother and feels a bit more powerfull as well. Common according to the workshop, since the cam timing is now optimal.

They also changed one of the pulleys in front of the engine..

I must say, this is one refined engine. Extremely nice idle and very low on mechanical noises when it is right.

There is one thing though, it seems I've had two sounds on cold startup. Rattling from tensioners and Ticking from something else. I've read several reports about this. At cold engine you can hear a slight tick, one blip on the throttle and it's gone. when warm it's completely silent, so we're just talking about the first few seconds after startup.

My car had an oil change not long ago, with something that I guess is Jag spec weight oil. I've read on the forum that a different weight oil might help on this. A few mornings when it has been cold (-2) the sound has been totally absent which does indicate that there could be something to this. What weight oil are we talking about then? The cold weight to 10 and warm weight to 40 or 50 perhaps? During winter it might be smart to stick with the jag spec weight though?

Do all XK8s have VVT? How do I know mine has, and is there a way of checking these, apart from buying and testing?

Still it's a real relief knowing that the tensioners are now the modern metal type on top.

Thanks for your help guys!

Cheers, Jarle

 

All XK8s have VVTs. The AJ26 engine ('97-'98) has off-on advance. The later engines, AJ27, has a variable timing VVT. They will make a click at a little above idle but that is normal.

Personally, I would not move to a higher weight oil, above 10w30, in the type of temperatures you are going to experience for the next few months.

 

Thanks Test!

Where do I find the engine number? Mine is a 98 car, but could still have the AJ27 engine I guess...

Will the early one make a click when the advance kicks in? I can clearly hear a click if I rev it a bit up and down when warm. And that click sounds very similar to the cold start click.

To be honest, I don't mind much about the problem. It disappears by a small throttle blip. But I still want to do some research to see if there is an easy fix. The small solenoids, are they placed on top of the engine? Are they easy to change?

Regarding the oil weight. 10w-30 is what I'll put in on the next change. The oil has just been changed, so I see no reason to throw out perfectly good oil.
Agree?

Cheers, Jarle

 

I had one thought today. Could the ticking I hear on cold startup be a valve lifter that sticks a bit until pressure builds up? I guess they are hydraulic?

Cheers, Jarle

 

No lifters . . . overhead cams pushing directly on the valves.

The VVT solenoids are on the top front of valve cover for the AJ27 and on the front of the valve covers for the AJ26. Might remove the electrical connectors and see if you still get a click but you are describing what would appear to me to be normal operation.

I have no experience with cold weather like Norway's. If it is below 20 degrees F. at home it is too cold to go out.

 

The only thing I could add is that I have noticed a light ticking sound that seems to be coming from the driver's side of the engine (left hand drive). What it sounds like can be described as similar to a sticky lifter (I know there are no lifters) or a small exhaust leak (I had headers on a car many moons ago and a pin-hole leak that I had sort of sounded like a ticking).

In any event the ticking only lasts for maybe a minute or less after startup and then goes away. I know that the XKR does NOT have the VVT.

Doug

 

There is a fuel vapor tank with a electrical valve in that area that has been the source of unknown ticking.

 

I have heard about that and I think it is located under the left footwell area? I believe I found some TSB somewhere about that and was going to ask the dealer to check this out when I brought the car in for the transmission recall/reprogram.

Doug

 

Hey Test!

Learning by the day here. I must say I'm very impressed with the low mechanical noise in this engine without hydraulic lifters. Thanks, then I don't need to worry about having to change lifters.

I've never tried my car in summer time, so I don't actually know if the sound is present then at all. Time will show I guess.

I tried removing the electrical connectors to the VVT and it didn't change anything. Like I said, don't worry much about this sound really, but I am curious on what it is.

Cheers, Jarle

 

Hey Doug!

This sounds exactly like the ticking I have. Does it go away if you blip the throttle? Like a tad over 2000 rpms? It's clearly coming from the top of the engine left side like you say.

Cheers, Jarle

 

Hmm... Could hardly be related to throttle input could it?
My ticking just disappears as soon as I blip it above 2000 rpms.
And it won't return until engine is dead cold again.

Cheers, Jarle

 

Hey Jarle,

I have never tried blipping the throttle--I just let it idle a bit and it seems to go away over a period of say a minute or so after starting. I will try the blip the next time I start the car and see what happens.

Doug

 

Would be interesting to hear if the same happens to your XK.
Just curious on what it can be..

Cheers, Jarle

 

OK! What is "blipping"?

 

Push the throttle for a little second, just enough for the engine to rev past 2000 rpms. As soon as I do that, the ticking sound disappears.

Cheers, Jarle

 

Is it in the engine or the relays located on the right firewall under the hood? I think you will find 5+ relays in that location.

 

I found a post on the XJ8 forum where someone posted a youtube video where you can hear what is described as the purge valve solenoid http://www.youtube.com/watch?v=8VNuCfv1Uiw

This is definitely NOT the sound that I am having and also does not seem like what Jarle has been describing. In my case (maybe also Jarle's) it is a much quieter ticking that sounds exactly like lifter noise in engines with lifters.

Doug

 

With the noise you are addressing you should be able to use a stethoscope to identify the location of this tapping. You could put the car in drive, foot on the brake and bring the engine up gradually and see if the noise continues. If it is a piston wristpin or a bearing it will get louder under stress. I had a 93xj-s 4.0 and I recall a conversation with Jag mechanic about a shim that is installed at the valve spring to prevent a valve tap but was unable to recall the exact reason behind the comment. See about getting a stethoscope.

 

This is what you need.

 

I think that Pep Boys sells these as well and I might just invest in one the next time I am shopping for auto paraphernalia.

Doug