New name for my boy's 2003 S 3.0 manual. I hear a rap, a rap a tapping.

My way smarter than this dumb move son, failed to change the oil and apparently developed enough of a valve cover leak to run low and start making noise. No low oil indicator came on.
I'm trying to trouble shoot as much as possible prior to tearing it out. 82k only had mobil 1 for the last 30 k at least. Idles like a dream, quiet, no sound. Only on increased revs to we hear a hard tap, not a deep knock! But a pretty solid rap, not a rattle. Certaily could be a mild rod knock. "Stethoscope on oil pan, valve covers, various engine parts provides no insight. No increase or decrease or any other indication that its near! Removed valve covers, cams look really nice. 203 - 209 psi on compression test.

Any sugesstions.

Are the lifters - followers - hydraulic and could one be weak. I would hate to pull the motor to find the problem up top.

It has been run very little to minimize damage if its a bearing. MY good buddy thinks its a wrist pin.

It's been sitting, but gotta get on this. I'm a new member, but have followed and enjoyed learning for quite some time.

Thanks in advance,

Gil

 

Had the same motor and symptom and sound= rod bearings shot. You could tear her down but less costly and efficient to procure a low mileage salvage ($1995).

 

Thanks for the reply. Probably will go that route

 

It will be the VVT see here very useful 2000 S-Type 4.0, Today my jag started making a clicking noise - FixYa

 

Guess it will pay to check the lobe clearance. I'm still curious about whether the lifters are hydraulic and how to test for that. I ordered a JAG CD and very little is covered about the lifters/followers.

Thanks

 

My sons 3.0 is a 2003 "m" after in the engine choices. Locally there are several low milage engines from 00 and 01. What is the difference? Are they usable?

 

They are not hydraulic in the old sense, they use hydraulics to rotate the cam see here it may help Cam-Torque Actuated Variable Valve Timing System - Tech Dept. - Car and Driver

 

I was looking for what may cause a rap or knock, not at all noticeable at idle, cold or otherwise, that I cannot hear at the lower end of the engine/oil pan. I have not driven the car, but increasing the revs causes a singular repetative rap. Like a mild knock. The running low on old oil may just be a coincidence (probably not). I'm trying to make sure that something is not wrong up top before essentially discarding this engine. Idles like silk, no noise. Cams and top end looks great, like it should. If I could hear a knock when I use my listening device against the oil pan, I would just pull & replace, but I don't. I do not hear it up top and it's not a rattle or ping. I have found some used engines, but would hate to install one no better than what I'm taking out.

 

If you'd otherwise swap it out.... maybe just drive it!

You might try recording the sound and posting the sound clip.

 

I hope it to be a malfunctioned VVC (both raps-knocks at idle and when revved) but understand a relatively quiet engine at idle versus rap or knock when revved. As jagv8 suggests: I drove the rapping 3.0 till the day she died.

 

My son who has generally been local, will be traveling. I would hate to have her die far from my easy help. It's a beautiful car that we want to be confident with.

Jag V8

I thought I did put the year model & engine in my signature. Guess I'll ad the 82 K milage to that, if it will help.

So--- thanks for all the replies. So -- It still could be the valves / Valve timing!!! I'm still unsure of what & how to test. I'm pretty resourceful so lay it on me Please!

 

Any suggestions on the best place to bolt my engine leveler when I pull the engine.

I have 4 flat plates & 4 chains

I'm used to the bulk of my big block. Everything looks so fragile. I'm trying not to be a barbarian.

 

Gil, private message Brutal or AVOS, our certified jag techs. They understands how the motor is pulled. Before doing so, can you bring her to a independent Jag tech for analysis?

 

I have the top pulled apart a bit. Figured it was last try before I pull her.