4.0 Valve Tappets & High Mileage Oil

[Kon]

Hi guys,

I didn't find anything in the existing threads, so created a new to ask about that.

For some time now, when I turn on the jeep (4.0 with about 125k on the odometer) I hear a metallic sound coming from the engine. It doesn't happen all the time and if I have to guess a pattern, I would say it happens when the engine is cold. The metallic sound is there for some time (from few secs to less than a min) and then the engine runs smoothly at idle.

My mechanic says it's the valve tappet of the 1st cylinder (the one closer to the the front of the Jeep, not the cabin). To tackle the issue, during the recent oil change (I change the oil every 5k miles and use Castrol 5w-30) we added a cleaner (don't know the brand or specific product but can ask), though I cannot report any finds yet as I need more time to understand if it had a positive impact on the sound.

I'm the second owner of the jeep so cannot have a clear view of how meticulously the PO changed the oil and I have to admit that some years ago I have not been consistent with oil changes myself, having left the same oil in the engine for maybe 12-14 months or 8k miles without changing it for couple of times.

I would like to hear;
- your thoughts on what else I should try as a solution to the issue
- how worried I should be about the engine's lubrication with what I'm experiencing?
- could the engine has underwent any serious damage?

Cheers!

 

[Gilaguy23]

I personally found on my 98/4.0 with 60K, the one time I used Castrol switching from Chevron Supreme 10/30 the engine made more racket. The noise is 99% likely a lifter bleeding down over night which is pretty common and not a huge deal.... unless it completely collapsed of course. Personally id not wee wee on Castrol products or any of the mechanic in a can products like the Lucas line of crap, just use quality oil and filters like a Wix or??. You might try a quality "high mileage oil" next service. A bit more detergents/additives/seal conditioners. Other than that drive it and be happy. Just my $.02 worth.

 

[pagrey]

Very common, you could try to switch brands or types of oil. Different additives or detergents work better or sometimes switching from one to another works. Mine does it when I push oil change intervals much beyond 3,000 miles. It isn't going to hurt anything, I wouldn't use additives of any type and it doesn't change the overall lubrication in any significant way.

 

[Kon]

Thanks for the input. So I understand your suggestion is to use a different brand of oil along with an additive and check out how the sound will change.

What about oil viscosity? Would for example 10w-40 instead of 5w-30 that is less thick help?

 

[pagrey]

My opinion is the tick is primarily effected by dirt and detergents in the oil and not really the viscosity but it can't hurt to try. Like I said before, personally I don't use extra additives in my oil.

 

[Kon]

Ok gotcha.. What would be your suggestion on brand/viscosity based on my mileage (125k miles), to see if I can source it locally?

 

[pagrey]

Cheap works best for me, 15w-40 if the temps don't get too cold otherwise 10w-30 or 5w-30 like you've been running. I don't think brand matters at all, the important part is trying a new one.

 

[Kon]

Thanks! Re the times were I wasn't consistent on the suggested oil change intervals. Could this has caused premature damage to the engine? I have been reading that regular oil change intervals are crucial and I not always been by the book there as mentioned above is the reason I ask...

 

[pagrey]

Could this has caused premature damage to the engine? I have been reading that regular oil change intervals are crucial and I not always been by the book there as mentioned above is the reason I ask...

I wouldn't worry about it, what can you do at this point? I've gone over a few times, it's no big deal.

 

[Gilaguy23]

Unless the thing was abused 125K isnt even broken yet 8k on a change every once and a while is not gonna hurt it either. Please, no additives to thicken it up like Pukas Oil stabilizer,STP or magic bla,bla in a can or whatever the crap is called. Todays oils are 100% better than 10 years ago and need nothing added. Valvoline 5/30 or10/30 high mileage is a favorite and good stuff. Personally Im a cheap bastage and 90% of the time run Walmarts 5/30 synthetic HM in everything, - temps to 100+. Quiet, 0 consumption issues and I go 5K between changes and everything has anywhere from 150K to 190K miles. I dont like Castrol, to much advertising BS and its made by British Petroleum. Liquid engineering like the engineering in their vehicles eh?

 

[03coloradowrangler]

by chance when the noise at cold startup occurs, if you shut down the engine immediately and restart the engine does the noise not reoccur at that point?

asking to confirm a similar description of what im seeing in mine. noisy as hell for up to a minute occasionally at a cold start but if I shut down and restart the noise doesn't occur.

 

[JKP]

by chance when the noise at cold startup occurs, if you shut down the engine immediately and restart the engine does the noise not reoccur at that point?

asking to confirm a similar description of what im seeing in mine. noisy as hell for up to a minute occasionally at a cold start but if I shut down and restart the noise doesn't occur.

Are you getting a loud metallic noise? Or just lifter ticking?

 

[Kon]

by chance when the noise at cold startup occurs, if you shut down the engine immediately and restart the engine does the noise not reoccur at that point?

asking to confirm a similar description of what im seeing in mine. noisy as hell for up to a minute occasionally at a cold start but if I shut down and restart the noise doesn't occur.

That’s right, is doesn’t. Have tried that as well.

 

[Kon]

Are you getting a loud metallic noise? Or just lifter ticking?

How can you tell the difference? I wouldn’t call mine loud. On the other hand I’m not experience enough to know where it comes from. I titled the thread valve tappet after translating in English the part that my mechanic suggested causes the issue (as explained in post #1).

 

[JKP]

My YJ had a lifter (tappet) that would stick and it would make a loud clank until it pumped up and unstuck.

Yours sounds more like the lifter(s) are leaking down a little and then pumping up fairly quickly. That could be worn or dirty lifters, or a bad anti drain back valve on the oil filter.

 

[Kon]

My YJ had a lifter (tappet) that would stick and it would make a loud clank until it pumped up and unstuck.

Yours sounds more like the lifter(s) are leaking down a little and then pumping up fairly quickly. That could be worn or dirty lifters, or a bad anti drain back valve on the oil filter.

Thanks for chiming in. What would be your suggestion on fixing the issue?

 

[Kon]

Btw, tappet and lifter is the same part?

I’m referring to this part as a tappet (photo from the parts manual), the lubrication of which my mechanic suggested is the cause of the sound.

 

[JKP]

Yes, tappet and lifter are the same.

Wait and see if the cleaner works. I ran a high mileage oil in mine and it cleaned out the lifter.

Be sure the oil filter has an anti drain back valve. Occasionally it is possible to get a filter with a bad one also.

 

[Kon]

Yes, tappet and lifter are the same.

Wait and see if the cleaner works. I ran a high mileage oil in mine and it cleaned out the lifter.

Be sure the oil filter has an anti drain back valve. Occasionally it is possible to get a filter with a bad one also.
View attachment 306360

Thanks! I had no idea that oil filters have a check valve. I usually use the mopar oil filter so I guess that’s not he issue. Any suggestion on cleaners?

 

[JKP]

Yes, the mopar filters have them.

I just used M1 high mileage oil. Most high mileage oils have extra detergent. I haven't ever used a cleaner additive.