warning lights on dash

[Dopo]

Adjustment of Inlet Valves V6 NS engine

After getting sick of my warning lights coming on each morning I final got to the job of adjusting the inlet valves on my V6. I did want the MM dealer to do the work as the car is still under warranty and yes that should not matter, but since no MM dealer would touch the engine because “I had LPG fitted” I went looking for a non MM service centre. Same deal, na not if it’s got LPG mate.

Even went back to the guy who fitted the LPG system but he came up with this story that he would need it for about 3 days, there are shims involved, a big job mate, cost will be over a grand. Got to be joking, just to adjust the valves? It only took him 2 days to fit the LPG system.

So after reading the other posts here about the number 2 miss fire issue on V6 LPG engines, time to get the tools out and do it myself.
The biggest part of the job is removing all the wiring and hoses that cover the engine. Once all that is moved away and the LPG bits move aside, note, not disconnected, just pulled aside as shown in attached pictures, you get the tappet covers off to gain access to the valves.

Then it was a 10 minute job each side to reset the inlet valves. Mine had zero clearance on all valves and one set actually had tension on the valve springs so valves slightly open. The engine has 127000kms and even though the car has had all its serving at MM, the valves have never been adjusted. Only the cop out audible method.

The attached picture shows the engine with the tappet covers removed. Note the top bank of valves are the inlet, the ones to adjust. I set them all to 5 thou on a cold engine. The bottom bank are the exhaust valves and are hydraulic, so no need for adjustment.

I could not believe that the MM dealer did not know that the exhaust valves were hydraulic and inlet adjustable. They also said the valves are adjusted by fitment of shims??? That might be the case on the diesel engine but not the V6. Yes I did make it clear to MM dealer it’s a V6 petrol engine. Goes to show how often they adjust valves. I am thinking, not often.

So once adjusted put it all back together. The only part I needed was the Mitsubishi OEM part, inlet manifold gasket Mitsubishi Part Number MR561584. Cost $23.00. I did buy a gasket kit from Repco but the tappet cover ones were too big, even though the catalogue showed for NS engine.
Might have been for the 3.5 litre engine.

I used the original tappet cover seals as they are those rubber ones and still were in good condition. While putting all the hoses etc back on I tidied up the routing of the LPG hoses, vacuum lines and wires. Looks much cleaner under the bonnet.

Result. No more warning lights even on the coldest morning when it would always come on, and engine is much smoother. In fact I had to check at idle it was in fact running. It was J.

Total time to do the job, about 12 hours but I took my time and washed, cleaned inspected the parts as they came off. If I did it again I would do it in a day, so 8 hrs all up.

Can anyone do it? I am a helicopter mechanic so no problem for me, but you would want some mechanical skills, knowledge as you are playing with a lot of important engine bits, wiring, sensors, fuel lines etc and you need to make sure it all goes back correctly. Modern engines don’t like bits not connected properly.

If you are not going to do it you self, this post should give you the knowledge not to be ripped off for a valve adjustment just because you have LPG fitted.

Thanks for the others who posted their experience with the number 2 miss fire issue. It helped me sort out my car.


Pictures: Inlet manifold off. LPG bits, top of picture moved a side. Note inlet valves at top of picture. All back together.

[chris 4x4]

Good to hear all went well. The good thing is you know the the job was completed correctly and you could spend that extra time and effort cleaning all your parts and assuring it was reassembled properly. Thanks for the info, useful for future V6 owners intending to tackle this job.

[Cecu]

well done mate!

it's annoying when the so called professionals don't know (or can't be bothered) to do the job and you have to do it yourself... but it's definitively great to be able to do it!

I personally wouldn't be game enough to attempt that

Cecu

[Delija]

After getting sick of my warning lights coming on each morning I final got to the job of adjusting the inlet valves on my V6. I did want the MM dealer to do the work as the car is still under warranty and yes that should not matter, but since no MM dealer would touch the engine because “I had LPG fitted” I went looking for a non MM service centre. Same deal, na not if it’s got LPG mate.

Even went back to the guy who fitted the LPG system but he came up with this story that he would need it for about 3 days, there are shims involved, a big job mate, cost will be over a grand. Got to be joking, just to adjust the valves? It only took him 2 days to fit the LPG system.

So after reading the other posts here about the number 2 miss fire issue on V6 LPG engines, time to get the tools out and do it myself.
The biggest part of the job is removing all the wiring and hoses that cover the engine. Once all that is moved away and the LPG bits move aside, note, not disconnected, just pulled aside as shown in attached pictures, you get the tappet covers off to gain access to the valves.

Then it was a 10 minute job each side to reset the inlet valves. Mine had zero clearance on all valves and one set actually had tension on the valve springs so valves slightly open. The engine has 127000kms and even though the car has had all its serving at MM, the valves have never been adjusted. Only the cop out audible method.

The attached picture shows the engine with the tappet covers removed. Note the top bank of valves are the inlet, the ones to adjust. I set them all to 5 thou on a cold engine. The bottom bank are the exhaust valves and are hydraulic, so no need for adjustment.

I could not believe that the MM dealer did not know that the exhaust valves were hydraulic and inlet adjustable. They also said the valves are adjusted by fitment of shims??? That might be the case on the diesel engine but not the V6. Yes I did make it clear to MM dealer it’s a V6 petrol engine. Goes to show how often they adjust valves. I am thinking, not often.

So once adjusted put it all back together. The only part I needed was the Mitsubishi OEM part, inlet manifold gasket Mitsubishi Part Number MR561584. Cost $23.00. I did buy a gasket kit from Repco but the tappet cover ones were too big, even though the catalogue showed for NS engine.
Might have been for the 3.5 litre engine.

I used the original tappet cover seals as they are those rubber ones and still were in good condition. While putting all the hoses etc back on I tidied up the routing of the LPG hoses, vacuum lines and wires. Looks much cleaner under the bonnet.

Result. No more warning lights even on the coldest morning when it would always come on, and engine is much smoother. In fact I had to check at idle it was in fact running. It was J.

Total time to do the job, about 12 hours but I took my time and washed, cleaned inspected the parts as they came off. If I did it again I would do it in a day, so 8 hrs all up.

Can anyone do it? I am a helicopter mechanic so no problem for me, but you would want some mechanical skills, knowledge as you are playing with a lot of important engine bits, wiring, sensors, fuel lines etc and you need to make sure it all goes back correctly. Modern engines don’t like bits not connected properly.

If you are not going to do it you self, this post should give you the knowledge not to be ripped off for a valve adjustment just because you have LPG fitted.

Thanks for the others who posted their experience with the number 2 miss fire issue. It helped me sort out my car.


Pictures: Inlet manifold off. LPG bits, top of picture moved a side. Note inlet valves at top of picture. All back together.

Hey,

I know this is an old post. I hope somebody responds. How did you go after one year? Did the lights come back after a while or? I'm having the same issue with the same car LPG too. We adjusted the valve clearance to .20mm which is a bit more then you did, but i still get the lights coming up with Number 4 cylinder misfire. The noise is gone though from the tappets.

[fewa]

Great post Dopo, this was a godsend to me, my 07 NS LPG paj became very hard to start, and the misfire on cyl no 2 code kept popping up, the engine has done 155K, after following your detailed instructions I found that all my inlet valves were under tension, no clearance at all, so yep reset the gap to .005 thou and cleaned up the LPG wiring as it was pretty ordinary, and bingo the car purrs like a kitten, the idle is smooth and she now starts very easily in this cold Melbourne weather, you are a legend, thank you.

[erad]

Looking at the photos, I can see that the inlet valves have adjustable tappets, but the exhausts don't seem to have any form of adjustment. How are clearances maintained? I guess they must have hydraulic lifters. Seems odd to me in this day and age of expensive and unreliable motor mechanics to have adjustable tappets at all.

[fewa]

Exhaust are hydraulic, on the 3.8, pain in the neck job to do.

[SIR]

Thanks for the guide Dopo, I adjusted mine yesterday they also no clearance. Car idles much smoother and has seemed to improved in fuel economy by 1L/100, I assume that some must have been open all the time.

I had the same issue with the aftermarket rocker cover gaskets not fitting, they were wrong around the bolt holes. I went to get genuine but no dealers had a set in stock (shows how often they replace them) so had to put it back with the original seals.
Car seems to crank slightly better as well but still takes a longer then expected time to fire.