4.0 v6 timing noise questions and options.

[Explorer_PL]

Hello everyone -
My 07 with the v6 (124k miles) is making a very suspicious rattling noises and the oil pressure light flashed (once so far) but that concerns me. I still need to listen to the engine what makes those noises but my fear is that the rear chain is slapping around since that's where the noise is coming from (I think).
Here are the questions:
If needed, I am ready to pull the engine out - that does not scare me, not much fun in it since it's getting cold outside, but doable.
Rebuilding the timing components - do not want to touch that part with a 10 ft pole.

If I have the engine out, and it's still timed properly, it has a full power, no noise when on the highway, just when idling, can I replace the guides and tentioners without disturbing that ?

I did the timing on my 4.6 and with the dots on the sprockets and phasers, and colored links on both chains, it was idiot-proof (me-proof )
I do not think the 4.0 is even close in simplicity to the v8.

My other thought was to pull it out before it self destructs and drop it at some engine rebuilding shop so they can do it for me. I think it's still a good engine with some life in it.

I was checking prices for remanufactured ones, and they start at $ 2,499 from what I see.

Please share your opinions and ideas.

 

[Tech By Trade]

Nope, once disturbed you need to re-time the entire engine. Due to a lack of marks, the only way to reliably do the job is with the OTC kit. It is possible to manufacture a timing kit, but purchasing the OTC kit is less time, and material consuming and economically feasible in the end. I also would not trust a shop with this engine unless they already have the specialty tools required for repair, and can prove they have done the job before. Many do not know what they are getting into before taking on this job.

 

[Explorer_PL]

Thanks Tech
Some shops assume it's just another regular timing job

I just saw a video where someone replaced just the tentioners since they are "external" and can be removed with 27 mm socket: one under the thermostat housing, and one in the rear.

Does that sound right ?

I always though the tentioners are under the front cover.

 

[07EddyB]

So I take it that you are going under the assumption that the tensioner seals have blown out and are dropping your oil pressure. There are other possibilities - like the oil pump is failing or the pickup is clogged. Perhaps a blockage in a oil galley. I would try to hook an actual oil pressure gauge to it and see what the numbers look like before pulling the engine.

 

[Explorer_PL]

Not pulling the engine based on my assumptions - been wrong too many times.
Yep, good idea to check the oil pressure - what point ?
What crossed my mind is that if the guides are in pieces in the pan, that may be blocking the oil pickup.

PS: My hope is that one of the accessories is making all that noise, AC comp bearing ??????

 

[Tech By Trade]

Tensioners are simple. They can be reached on the front driver's side under the intake and the passenger rear from inside the wheel well. A couple hour job. Also, the lower oil pan uses a reusable gasket. Next oil change drop the pan and inspect for reminants of the timing cassettes or springs from the primary tensioners.

 

[07EddyB]

Not pulling the engine based on my assumptions - been wrong too many times.
Yep, good idea to check the oil pressure - what point ?
What crossed my mind is that if the guides are in pieces in the pan, that may be blocking the oil pickup.

PS: My hope is that one of the accessories is making all that noise, AC comp bearing ??????

What point - I think you're asking what numbers to look for. Honestly, I don't know. I would look at them though - and see how they compare from a cold start to a warm engine - and how they look at idle versus higher RPM.
Before I pulled the engine I would drop the oil pan if that's what you think is happening. At the end of the day, do you think a V6 at that mileage should have that problem? I don't know - but I would be shocked if my V8 had that problem at that mileage. Again,I don't have a V6 so I'm not up on the issues that they have.
If you suspect an accessory, then take the belt off and run it for a few minutes. Quick and easy.
You read about my latest saga on my V8 - when I pulled the valve cover I could see the top chain guide and it looked good. If I had a borescope camera I could have looked at both of them but the top looked great. I'm not sure what you can see with the V6 valve cover pulled off but I would definitely try it if I were you. Maybe buy a cheap borescope.
My point is - we all know what the most common problems are with our engines. And we tend to focus on that and assume the worst. If you followed my latest thread, you know that a mechanic attributed my lifter noise to insufficient oiling to my right head - a common diagnostic for my engine. I pulled the valve cover - found a locked up roller on a follower - replaced it - and I've enjoyed a quiet engine ever since.
So - do what you can. Check the oil pressure - pull the valve cover - drop the oil pan - do the relatively easy stuff before you pull the engine.

 

[Explorer_PL]

By point I meant where to plug the pressure gage.
Brilliant and simple idea about taking of the belt - thanks.

Lower oil pan ???? - how many pans are there ?
Gosh, this engine is an "engineering marvel".

 

[boominXplorer]

Don't replace the tensioners without at least setting the engine to tdc. It's almost best to take the valve covers off and make sure the tensioner side has all the slack before swapping them.

Also like mentioned previously take the belt off and run it to rule out the tensioner and pulleys. On newer say 06+ motors the only under 125k mi failures I've seen have only been from very poor maintenance.

Do you have any oil leaks? Have you been solid on your oil changes?

 

[Tech By Trade]

There is an upper cradle and a lower pan on these things. The cradle needs to be pulled to get at the oil pump and main caps. They are quite the Rube Goldberg.

 

[Explorer_PL]

Nothing of an update so far. It started leaking antifreeze on Friday and I traced it to the vacuum controlled heater valve on the passenger side, the neck of the lower port was cracked. While I was removing the intake to get there I discovered that all 4 wires leading to the TPS were bare and had no insulation, so that may explain the uneven idle. Got a new valve from Advance for $ 19 this morning so when I put it back together, I'll take the belt off and run it.

And thanks for all the suggestions so far, appreciate that.

 

[boominXplorer]

Unpin the wires one at a time and put some shrink-wrap down each wire.

 

[Beachcomber86]

While I was removing the intake to get there I discovered that all 4 wires leading to the TPS were bare and had no insulation, so that may explain the uneven idle. Got a new valve from Advance for $ 19 this morning so when I put it back together, I'll take the belt off and run it.

And thanks for all the suggestions so far, appreciate that.

You just found a big ole bug-a-bear there. You'll be real happy once you cover those wires!

 

[Explorer_PL]

Put everything back together last night. Took the belt off and started it. Sounded much better so something from the accessories is rattling. I still heard some noises from under the valve covers, and those were probably valves working and I assume it's normal. Maybe I'll record it and post it somewhere. I will not do anything now yet, maybe the oil pan inspection if it gets warmer, but they forecast some first snow for the weekend here so will see how it goes.

And I owe some answers to BoominX:
no oil leaks, and I got the truck at 116 k over a year ago, it's at 124k now so not sure of oil change history. I do it every 3-4k since I go it.