Over the past few weeks I've noticed there seems be a split-second clattering noise from the engine when I start the car. Its the exact same noise you get when the engine is oil deprived after a full oil change. It happens about 60% of the time, mostly when the car has been sitting for more than an hour. I tried Castrol Syntec 0w30...got worse. Then I put in Castrol Syntec 10w30...a little better but the noise remains. Read that it might be a problem with the anti-drainback valve on the oil filter, so I tried 3 different filters...no joy. Tried oil stabilizer and Seafoam treatment (not at the same time)...noise remains. Maybe I should drop the pan and check the oil screen? At this point, I don't what else to try. Besides that split-second noise, the car runs fantastically with 128,000 miles.

 

Could the noise be a hydraulic tappet (lifter)?

I had this once on a Saab and it went away after a while.

 

It sounds like it might be, but its been going for close to a month now. Again, mostly only on cold starts.

 

when you say you tried different filters, were these the genuine Jaguar part with the valve, or other brands?

 

My mechanic has always used Bosch, which I couldn't find in any local auto stores. So I tried a Fram (got worse), Purolator, (better than Fram), and finally Wix (same as Purolator basically). All three have the anti-drain back valve, and I've never had issue with my old mechanic sourced Bosch filters.

 

Alot of us here some startup noise from VVT solenoids. I hear it alot on my xk8 w/ 142k miles, but never on my 55k xj...both with the same size engine of course.

 

no VVT on the Supercharged engines, surely?

OOI, I was having some brake work done in my Smalltown branch of a lube/tyre/brake/exhaust chain last week, they quoted my £40 for an oil change to Jag spec, which I thought great value, but said (there was a lad there who had recently moved from the branch in nearby Poshtown which has lots of Rs and XKs and Aston Martins) that they could only do it if I brought in a genuine Jag oil filter with the non-return valve, as nothing else would meet the maker's spec and it was not available through their central warehouse. Apparently is a question which crops up frequently in Poshtown. He specifically mentioned oil draining away if no non-return valve present and had already demonstrated his familiarity with the NA and the SC versions of jags.

I looked on an Jag Parts specialist site and the genuine Jag filter for my 4.2 Supercharged is £14.23 and the OEM filter is £11.24, so I decided there was not much of a saving and ordered a couple of the Jag filters.

It might be that the OEMs are in fact identical, but for a £2.99 saving I can't be arsed.

 

I'm not convinced a Jaguar OEM filter would help. Like I said, my car has always run on Bosch filters. Maybe I should source a Bosch online and give that a shot, as none of my local stores carry that specific type.

 

what do filters cost where you are?

ordering from an online specialist, I find there is only a small difference for air/oil/cabin/petrol filters between the jag and substitute brands. There is however a noticable saving if you buy the non-original boxed service kit of filters, drain and spark plugs. It currently seems difficult to buy non-jag sparkies here.

 

I beleive the VVT works on oil pressure and if the pressure is low they make an awful sound.

 

That is my understanding also. What could be causing this? Bad oil pump?

 

Sounds like you may have bad secondary timing chain tensioners. You could pull the valve cover and see if the chain has any play.

 

If that were the issue, wouldn't it make that sound 100% of the time? Not just when cold?

 

I have had lots that make a ticking noise on start up on a cold engine. The upper tensioners are supposed to hold the oil pressure an keep tension on the chain, when they Get warn the oil pressure leaks out causing a tick until oil pressure reaches the tensioners and the slack in the chain is Taken up

 

The sound is not a tick. Its a loud clattering racket for literally only a second or two, then the engine runs and sounds perfect.

 

FWIW, I have the identical 'clatter' most of the time when I start the car ('06 XJR). Same sounds has been there since I bought the car 2 years ago. Frankly, being rather mechanically un-inclined, I thought the sound was a normal start-up sound. I'll be curious also to find out if this is not the case and how we resolve this.

 

Maybe unrelated to your issue, but I also noticed same clatter during a second when starting the car after several days unused. When starting after only one day, don't have the noise. Could be (in my case at least)some bigger oil draining during a longer period of not running the engine. I use Castrol synth Magnatec 5W30.

 

If it only happens after sitting for several days, it could be considered a normal sound. Interestingly, its been nearly two seeks since I last changed the oil and filter, and the noise is slowly decreasing. It was really bad before, where I was getting it at almost every startup, even if it had sat for less than 10 minutes. Now, if the engine is still warm at all, it starts up strong and smooth. In the mornings, I still hear the clatter, but it seems to be getting quieter. This morning I barely heard it at all.

 

I've noticed the clatter myself, but I'm not at all convinced it's internal. Mine comes across more as something loose in the starter/solenoid/engage gear area.

 

I think the timing chain tensioners have a tension spring or guide wear problem that is letting off too much chain pressure on shutdown. As soon as the oil pressure rises, they tighten up and quiet down. I would pull the valve covers and check this out, it could develop as a problem.