Got a new 4.7 wj just I've a week ago, had to put a new starter on as previos one was burnt out. Now the engine is ticking, louder and faster with the revs. Also when I slow to stop at junctions the oil pressure drops to 0 and the engine management light and check cage light flash on. Starts fine straight away and runs ok apart from the loud ticking as long as the revs are on it. I just gave her a full engine flush and new, royal purple oil, and still no change.
O and no fault codes showing up

Looks like it's goin to be an expensive visit to the dealer unless anyone has any ideas?
Cheers

 

I'd put a mechanical gauge on the oil pressure tap and confirm that the pressure is low. From there, it's most likely bearings if the pressure is confirmed as low.

 

Yes check with a mechanical gauge first. Also another thing my friends 2000 cherokee did the same thing your describing it would tick louder under stress and loose oil pressure ended up being his whole cam sensor mechanism went out

 

Would a bearing problem cause the low pressure? Or would that be a separate issue?

 

Also I forgot to say the engine only has 64k miles.

 

It could be a bad pump bearing getting hot then expanding an starting to seize but not 100% that is it problem.

 

Been looking up a lot of forums etc and a faulty oil pump sounds like a good cause

 

The sleeve/babbit bearings on the crank, connecting rods and camshaft will cause low oil pressure if they wear or burn.

The oil pump, unless it catastrophically fails because of a broken drive shaft will usually be able to maintain pressure if the bearings are good. It is a positive-displacement style gear pump. It will move a fixed volume of oil per rpm regardless of the back pressure. If the bearings are worn out there will be too much clearance for the proper oil film to form and it will knock.

 

Thanks all for the replies

 

Thanks for all the help. Had a dealer check it over and they said the heads had been off it recently and it had a new radiator. Doesn't sound good. I think the guy who I got it fro
Knew it was a dud. Turned out he was a dealer pretending to. Sell private. I threatened legal action and managed to get my money back from him.
Picking up another 2002 overland next week. Hopefully more luck with it lol

 

it sucks, but good deal for you anyway. Very surpised he took it back, guess he is gonna rip someone else off next.