Hi,

I getting a loud, what sounds like timing chain slap on startup, which only happens if I don't start the car for a couple days and it's about 50 degrees outside (only happened twice); and it will last about 30 seconds and start fading away for another 10 seconds or so. Engine runs great during and after it's slap ends. The 1998 Xk8 has about 50,000 miles on it and had the primary guides and secondary tensions changed at about 30,000 miles. Can I just try STP engine treatment or change the oil to 10-40 or 10-20 and see if this helps???? Or should I just let the car sit until I get a better handle on what is wrong and before the engine blows up on startup???

Thanks,
-Art

 

You have got to change those secondaries before the chain skips teeth and valves meet pistons. The replacements may have been plastic body version 2 which are no better than the originals. Regardless of what they are, they need to go. The next time you start the engine may be the last time.

 

I replaced the secondary's about 4 years ago, but I was thinking the springs in one of them must be weak or messed up. I do have to start it one more time to drive it to my storage unit, where I can work on it. Did replace them myself four years back, so no problem there, but maybe I should tow it to be on the safe side - I do have AAA... I did notice after the oil change, about two month ago, on start-up, the ticking of the chain was a bit up in volume, for the first minute or two, until the oil started flowing, than engine was quiet after that... I'm guessing that was my first sign something was wrong. I'm going to tow it !!!!!!!!!

One more thing: What brand or make of tensioner is the best to buy, because whats in there now, I think I bought on ebay, so maybe there not a good place to buy these????

Thanks,
-Art

 

It's been a few years since I replaced any, but the ones I used then were purchased from Ford dealers ans used in the Lincoln LS1. I think if you want genuine Jag parts SNG Barrett would be a good choice.

 

RJ237 - Thanks for the advice... Car is safely in Storage, awaiting new tensioners. :-)

I noticed you had a Maserati Spyder Cambiocorsa... I'm thinking about getting one and wanted to know how you liked yours; parts hard to get and are they as reliable as Jags, for the year 03?

Thanks,
-Art

 

make sure your oil filter anti drain back valve is working. fords are notorious for having misdiagnosed chain noise because of a cheap filter

if you replaced the primary tensioners the problem could also be there. the ratchet and o-ring could’ve both failed and it stays retracted until it builds pressure. not a huge deal. open up your valve covers to make sure you have the latest tensioners

 

xalty; Thank You for the advice on the oil filter... The engine did seem louder on startup, timing chain wise after the last oil change, and the strange thing is, I had to wait in the waiting room a long time, because they did not have the oil filter in stock, like they normally do. The tensioners are the most recent ones, only four year old, but this metal to metal noise on startup was loud, than faded away after about 30 seconds; So, I'm definitely going to change those out, before I start the car up again, and keep my fingers crossed!!!!

 

The primaries do fail and cause the long guides/blades to 'slap'!!!!!!

The primaries are plastic body as well as the original secondaries and the check valve in the tensioner fails.

The primary guides/blades are plastic covered and deteriorate.

 

motorcarman, I'm hoping it's not the primaries, because that was a major job I did on this car, about four years ago... I'm hoping it was one of the secondaries, that needed to build up oil pressure before slapping stopped... And again, they are pretty new, but this time I'm buying OEM Jaguar parts. And I'm going to change the oil and filter before I start the car again, to be on the safe side... <grin> I will update this thread when done, but might be next spring, but I am itching at the bit to fix it next week.