When I start my '00 Pajero (12-valve 6G72) in the morning and the engine is cold, it sounds/runs like a tractor. It bogs down, and although very rare, itcan stall on rare occassions.The motor acts like it's going to die anytime soon, and the same symptoms get worse when you shift into reverse or drive. Once the engine's warmed up, this problem goes away - but then I have another problem.

Acceleration is rather poor and there is a vibration issue. Sometimes it accelerates pretty well and other times its a real dog. I routinely service my truck, as per the service manual, so that isn't really an issue I would imagine. In an effort to tackle the problem, I replaced a whole list of items. Off the top of my head:
[ul][*]Spark plugs[*]Distributor cap[*]Spark plug wires[*]Timing belt[*]Emissions solenoid[*]Engine idle resistor[/ul]
I also removed the EGR pipe and valve, which had a fair bit of carbon in them, and cleaned them out. Upon replacing the idle resistor, the symptoms I experience in the morning have improved only slightly - but have not gone away completely. I also had my kick-down cable re-adjusted, because somebody was telling me that is most definitely what causes my acceleration problem. The shifts have certainly improved, but the acceleration problem is still there. Also, if I'm standing at a stop light with the transmission in drive and the brakes applied, the truck shudders a lot. It's reduced if I shift into neutral, but it is still there.

I was cleaning the throttle body a few days ago, and I was tempted to disassemble it, because it was dirtier than usual. The inside of my manifold was caked in carbon, and the throttle body itself was rather dirty. That being said, there are 3 vacuum lines built into the throttle body, labelled A (facing the front of the vehicle), B and C (facing the windshield). I sprayed throttle body cleaner in the lines, and it squirts through A no problem and the cleaner comes out from behind the throttle plate. B is completely blocked (cleaner sprays right back) and C sprays some back, but some of it does get through. I had my mechanic check the vacuum lines and he pointed out that there is no vacuum from B or C and very little from A. Could this have anything to do with my problem? Thank you.

 

Do a compression test and check if your coolant is low, sounds like a symptom of a headgasket.

 

I'll give the compression test ago, thanks! Although I never had any problems with the coolant going low. Are head gaskets difficult to replace?

 

hav u tried those fuel injector&carburetor cleaner which u pour into the gas tank?
i helps me solved my rough idling problem.

can u describe the vibration in more detail.
vibration can be caused by a lot of things and can appear at different condition.
do you feel it on the steering wheel or the whole vehicle vibrate?
each condition show different problem.
could be the mountings,coupling,even the rims can cause vibration.

about replacing the head gasket,its not something we can do on a free evening.
leave it to the mech.
but,if there is no problem then there is no need to repace it.

 

4G54,

I've actually tried Marvels Mystery Oil through the gas tank. I wanted to Sea Foam my engine, but Sea Foam isn't available locally and after much research, I found out I can use MMO through the brake booster line too. I did that and my truck smoked for an hour and a half. To top that, I've treated my engine and transmission with Auto-Rx, which has made a big difference - but again, nothing to solve my vibration issue. That being said, I've also replaced my engine mounts. One of them was slightly damaged, but even after the new ones were fitted, it didn't solve the problem. I also cleaned my MAF, IAC and throttle body.

The vibration is only felt when the engine idles and is most noticeable in gear. In park or neutral, it is still there - but not felt as strongly as it would when in drive/reverse. It causes the entire vehicle to vibrate. When I'm at a stop light for instance, and release the brake to allow the vehicle to move forward, it surges forward like a manual with the clutch being operated improperly.

If I pop open the hood, I can clearly see the engine shaking from side to side. When I took it in for a steering alignment and went under the truck whilst the engine was idling, my transmission was vibrating (transmission mount is new as well) along with my driveshaft. T

 

How many miles are on your Pajero? What are the temps in your area?

The ticking in the morning is probably attributed to the VLA's (Valve lash adjustors). What oil are you using?

My next guess for the studdering at idle would be the catalytic converter...

 

How would a catalytic converter cause a studder at idle???

 

A restricted exhaustwouldn't cause an engine toidle rough?

 

A clogged cat wouldn't cause a rough idle you, a clogged cat would cause a lack of power on heavy accel.

 

[/ul]
With the list of items replaced and the ongoing idle/acceleration issue, I don't see why the CAT is so far out of line...depending on the mileage that is.