2007 XK 4.2 NA 90,000 miles
Not sure if I'm being paranoid, car had't been started for a week in the cold weather. I started it and flipped open the bonnet while waiting for it to get up to temperature. When the coolant temp got to about 50 deg C I noticed a strange noise. Took it to my local garage to have a look but by then the engine had warmed up and the rattle had disappeared.
I did another cold start this morning and same rattle started as coolant temp got to around 50 c. Attached video is with engine cover removed. The noise is most noticeable on the top left side (facing forward).

Is it the tappets or something more serious like timing chain?
Oil level is midway and oil condition is good. The noise is not noticeable inside the car, or with the bonnet shut.
You advice would be really appreciated!

 

Chris,

I'm not clear whether you are suggesting the engine is quiet on initial cold start and the noise then develops as it warms OR the if noise is present on cold start and disappears as it warms .......

The cooling system is low volume/high flow rate to promote rapid warmup but will be taking a couple of minutes to rise on the cold mornings we've had in England this week.

Are you using an OEM filter or aftermarket? Several aftermarket filters that FIT don't have the internal non-return valve which prevents drain back so the pump has to first fill the filter on a cold start before oil pressure builds and this often causes valve or timing chain rattle.

However, if I had any doubts about timing chains or tensioners, I'd do a visual inspection a.s.a.p. as the consequences of failure are usually terminal.

Graham

 

It sounds to me like the tappets are a bit noisy until the engine is up to temperature. I suspect that the valve clearances need re-shimming but it's not an urgent fix.

Richard

 

Have the engine oil and filter changed before doing any further diagnosis. Use a Jaguar filter to avoid drain back.

If the noise persists after the oil has been changed, remove the cam cover and inspect the secondary timing chain tensioner and tappet clearances. I have encountered broken secondary timing chain tensioners on the AJ33.

 

Thanks everyone for the great advice, I had my local garage change the oil 6 months ago, it’s possible they may have used a non Jag filter. I’ll get the oil and filter changed and keep you posted….
Many thanks!

 

I have read that the Motorcraft FL 2021 is the same as the OEM filter.... Agree / disagree??

 

Do the feed holes have silicone flapper valves instead of just open holes?
I don't know, just posing the question.

 

Use Mahle, Mann or Bosch. The rest range from damifiknow to absolute **** (thinking of you, Fram....) Or buy Jag's, which I think is Mahle. Could be wrong, but it sure as hell ain't Fram.

As to Motorcraft, it's well regarded in this review https://www.cnet.com/roadshow/news/best-oil-filter/. Made by Purolator. Rockauto has it for $4.50. But then it has Bosch for 5.50 or so.

 

Looking at the workshop manual for the 4.2 engine the horizontally fitted filter looks to be level with the bottom of the sump & the oil pump is fitted fitted on the front of the crankshaft, which is higher than the filter, so an anti drain back valve seems somewhat redundant?

 

It's easy for a diagnosis to go off the rails if you're not careful.
My 2007 XK does this on occasions. In my case, it's the PCV valve situated behind the oil fill tube with the electrical connection on it in your video.
It bangs on and off just like that.

 

It probably is, since this implies the filter is permanently charged with oil. That said, if a manufacturer is so sloppy as to provide a filter without drainback prevention, it's probably isn't worth buying.

 

Learn something new every day. Can't believe this is the first time I've read this. Thanks. I've only used WIX because OEM supply turnaround has been slower than me. I'll order early next time.

 

Its the VVT pin. My 2008 RRS with the AJV8 has been doing this for 4 years straight. Ill eventually replace the entire VVT system. The best way to prevent this from ever happening is oil changes done at the right intervals before it happens. Ive done all I could, filters, oil treatments, different viscosities, and short of installing an pressure priming system. I can explain more if it interests you, but it happens on the AJV8 more often than reported.

 

I have a Triton motor in my f 250 which has the typical tensioner issue where the seal fails and the oil leaks by causing the dreaded "startup rattle".
I have found that if I jog the motor quickly and wait 15 or 20 seconds for the oil to get up to the top before actually starting it, I can avoid the rattle. Is there any way to jog the motor with the brake pedal/push button start up? I would like to be able to do that just for good measure after longer periods of not starting it or winter storage.

 

The point I was making is that with the the filter on the 4.2 engine being below the crankshaft it's not going to drain empty when the engine is stationary, so Graham's point of a filter without an anti flowback valve means it has to be refilled on starting the engine before oil pressure builds isn't valid.

Unlike the 5.0 engine where the filter is fitted upside down at the top of the engine the oil in it will drain out through the crankshaft journals & it will need to be refilled when the engine is started before oil pressure builds so again an anti flowback valve is redundant.

 

That also is a strong possibility and more likely than my valve clearances suggestion. Either way, I think that the cams are the most likely area to focus attention on.

Sorry ... forgot to quote but referring to VVT pin.

Richard

 

VVT rattle only lasts a second or two upon start up. It doesnt keep tapping while you drive. So how long does the rattle last?

 

I think what he's saying is, the filter canister drains at rest, so the pump can't move any more oil up into the top end until the filter canister first refills, and simultaneously the top end empties itself on startup faster than this happens. It makes sense to me -- it's happened to me on other engines. No lifter noise just after turning over and then it kicks in 2-3 seconds later and rattles for maybe 30 seconds. If I didn't regularly turn over my saab's 4-pot I could have grabbed a video of it for this post.

 

I haven’t driven it far, but it did seem to clear once the engine is fully warmed up.
I had the oil and filter replaced today and specked oem filter.
a very cold morning again this morning - the engine starts quietly, then as coolant temp ties to about 30c I get a loud click every few minutes and the tappet noise starts, then at about 55c it quietens. At 70c it came back again!
I have captured another two short videos:
1. There is a loud click at 4 seconds in… this happens every couple of minutes as the engine is warming
2. The tappet noise is clearly audible when car is up to 70c, I didn’t drive it so probably not fully warmed up.

Is the VVT pin a serious issue? Should I avoid driving until I can get it fixed?

 

That probably explains the loud click in the first of the 2 videos I posted this morning -
I will have a closer look to confirm, many thanks!