Hi Guys… I need real help and advice for you experts….

I have a 2002 Pajero (Montero in US I think) 75W with a 6G74 3.5L V6 engine 24valve…. (Jap import)

In complete blindness I never ever changed the oil for years (totally my fault) and now have a hefty issue.

Essentially my oil pressure light came on and now stays on… I changed the oil which was incredibly soupy…. Have flushed the car out with oil 6 times in a row including using Mitsubishi engine Flush twice… leaving Magnatec 10w40 in the engine.

Have changed the filters of course and also changed the pressure switch twice and proven they both work with the use of compressed air and a continuity tester…. STILL NO OIL PRESSURE (light stays on)

Car runs essentially fine but VERY noisy and “Klackety” from the lifters although oil is quite clean… obviously there is no oil getting into the cylinder head rockers…

So I took the oil filler cap off and stuck in a long Philips screwdriver and twizzled around a bit… out came VERY gunky and semi solid oil residue, very thick and gloopy… to me meaning that no nice oil or engine flush is getting into the the heads, it seems very dry in there…… so they need a real good clean as I think all the small oil-ways must be blocked.

I live in Africa (Botswana ) and a mechanic will cost a fortune and probably suggest a new engine…

What I would like to do is remove the cylinder heads intact without removing the rockers or anything and take a while to clean them with diesel and compressed air until I can assure myself that all is well. Then put them back with new gaskets

I would rather not dismantle the head itself in any way as this may be effected by my reasonable inexperience in working on an engine like this (I do have the tools)

Is it possible to remove the heads and clean like this?.... Will I encounter the need to remove the timing belt or camshafts or anything else? and if so is this ok for a reasonable home mechanic?

Is there a step by step guide anyone knows of to do this?

Any advice is very greatly received

Roger

 

You can't take the heads off the engine without taking the timing belt off.

You really can't clean the rocker shafts and valve lash adjusters without disassembling them. Lots of info and pictures here https://mitsubishiforum.com/forum/mi...removal-48920/

 

You can take the heads without removing camshafts off the engine, but i agree with Larry4406 - you will not be able to clean rockers and lifters without disassembly. If the oil gunk residue is as bad as you describe, you need major cleaning. The issue may be not even in the heads. It may be an obstruction in main oil galley or for that matter a failed oil pump. Do you know if it works?

 

HUnterD

Thats a very good question....

is there a way of telling if the pump has failed without dismantling the engine?

 

You can remove the oil pressure sensor and install the analog pressure gauge. That will show if you have any pressure build up after the pump. If you have no pressure there - you have a problem with the pump.

 

Thats very helpful ....

I have installed a new pressure sensor switch which I know is working as I have tested it with current continuity and a small amount of compressed air... seems to work fine

When installed in the car, the oil light stays on all the time, it used to fluctuate a bit.... from what you are saying would this act in the same way as a pressure gauge, in that its registering low pressure... therefore the oil pump has definitely gone?

 

That is likely. If you can, try the gauge installed in place of the oil sensor. If the pump is no working that will explain the lack of lubrication on top of the heads. Unfortunately that could also mean that you might have more problems with the engine related to lack of lubrication.

 

You can remove the rocker shaft assemblies without disturbing the heads or timing belt.

Remove the upper manifold components like you would do to change the spark plugs, then pull the valve covers, then remove the rocker assemblies and clean accordingly.

If you then removed the lower oil sump (assuming two piece pan) you could then clean the oil pickup and check for debris. You could build an ENIMA (see my rebuild thread) and force solvent thru the oil passages from the pressure sensor port to clean the block and heads all while catching the drainage out the bottom pan. Lastly reassemble, pressure lube with the ENIMA, then restore to service and change the oil soon due concern for residual solvent hideout.

 

Larry4406

That ENIMA is a brilliant idea and just what I need to ensure that oil is bet to and through the rockers.... thats what I am going to try... I guess I could use diesel for the solvent?

Now if I can just figure out a reasonable way to get the sump off... its definitely one piece with the axle on the way... thats the job for this weekend.

 

Thanks. I stole the idea from reading some other posts but improved it to my liking. I also gave it the funny name as a pun on the Mel Brooks movie where the doctor's solution was to give the patients enimas.

Make yours longer so you can hold the full oil capacity. I screwed up and was about 3/4 quart short. When pressure lubing don't let air bubbles get in.

I think diesel would be ok for the solvent. The manual recommends it for cleaning the valve lash adjusters.

Good luck and keep us posted.