Tapping on cold start

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Nov 19, 2009
TX south plains
Hopefully this isn't a silly question but here goes... So far so good on the first winter in the XJS (of course the lack of snow has helped). Haven't had any starting issues at all. However, there is one thing i've noticed. When I have started it cold there is a slight tapping sound until it warms up. Also until warmed up, the oil pressure is up. It usually settles in to around six on the guage but now is up to about seven or a scad over. I'm running Redline 5w30 in it changed about a month and a half ago. Should I be worried about this?
You listed Red Line 5W30 as your oil which IMO is the best brand of oil money can buy. What oil filter are you running? Because it sounds like the anti-drain back valve is draining back.
As far as your oil pressure, it's normal for it to be higher in cold weather. The oil is thicker when cold... As for the tapping, that could be mechanical, your oil could be the wrong viscosity (too thick for the temp), or the filter may have a defective/substandard ADBV. Easiest and cheapest is to change the oil using the proper viscosity as recommended in the owner's manual, and a filter with a silicone ADBV, if available for your application. *EDIT* I just re-read you post and saw you recently changed the oil with RL 5W-30...so that probably isn't the issue, but the filter could still be the culprit.
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Does tapping sound last a long time, until the engine is warmed up? Running 5w-30, oil pressure should be ok. Agree with filter comment except that bypass valve may not be sealing. Does XJS o/f use a bypass valve? If yes, change oil filter to a dealer oil filter.
The tapping goes away when warm and I didn't notice it when it was warmer. This is the first time I tried a non-OEM oil filter, went with Wix instead of the Jag unit. Oil's actually thinner than most run but went down a little due to using Red Line.
BINGO!! Always ask that question what was it like with whatever, that will tell you where to start otherwise you kinda waste time imho.
Originally Posted By: daman
Did it do this before with other oil's and filters?? what filter you running?
It's really pretty normal for cars with hydraulic lifters to do this. My 325 will tap very lightly for the first few minutes... but it's so quiet you can barely hear it. I'm running M1 0-40. I wouldn't worry a lot about it.
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