5 Cylinder V6

[88GreenVN]

I have a 5 cylinder V6

The 89 Green sedan when purchased almost a year ago now had a bad miss when I got it. Fiddled here and there with new plugs, leads and some injector cleaner which made it run alot better. But it still has a miss in it.

Car has plenty of power. I'm thinking it's not a burnt valve as it revs nice and takes off no problem (thanks to a greenfoam tune)

I've got the econnomy down to the 12's (from 18's) L/100kms. O2 and temp sensor fixed most of that.

When you bring the idle up to 1500 the miss is intermittent. (burnt valve would be consistant I would think)

I thought it may have been No 5 as when I took the injector plug off it had the least effect. BUT on close inspectoion of the lead it was not even on the coil plug properly - pulled back into the rubber boot. The top of the coil pin was a bit corroded. Cleaned that up and new plug lead for No 5. Re tested the injector plugs off again and No 5 had the least effect again. Changed plug again - but no change. When I pull the injector plugs off all the others the engine almost stalls every time.

I swapped over coils (has the 3 small units) to see if I could move the problem - but no. Could not really tell.

The harmonic balancer looks new. Can the CAS cause a miss? The car dosent stall at all.

It looks like it's a recon engine as it has tags on the rocker covers to that effect. Car has done well over 350,000 I'd say.

[HARVZ-6]

whats the compression like in each pot?

[Pub247]

i'd agree check comp and/or hook a vac gauge and see how it goes.
Is it a s1 aswell shane? what tags does it have on the cover?

My wagon's miss has come back again i just deal with and say it a v6 damn most annoying things about them

[davway]

id say you might have a water leak into a cylinder which is causing a miss fire.
i had exactly the same symptoms with a XF and it was the head gasket letting the smallest amount of water into a cylinder.
upside to it: that cylinder was clean!

[Pub247]

id say you might have a water leak into a cylinder which is causing a miss fire.
i had exactly the same symptoms with a XF and it was the head gasket letting the smallest amount of water into a cylinder.
upside to it: that cylinder was clean!

lol nothing like a steam clean to get rid of carbon. after a while itll start to corrode the alloy though.
But yeah headgasket is another possibility

[88GreenVN]

Not losing any coolant. No milk in the oil.

Same oil for last 12 months.

I've ruled out ECU & Memcal as I've tried several already

[Pub247]

ruled out coil packs and dfi that fixed my wagon for about month or so

[88GreenVN]

It's off the mechanic's tomorrow for a compression test on No5. This is the cylinder that has the least effect on the engine when removing the injector lead.

The car is running very poorly at idle chug chug chug. But has plenty of go in it. It dose not have a typical fluff fluff fluff from the exhaust when an engine has a burnt valve. But all the electrical but check out OK. All the plugs are the same colour. Leads are new. Swapped over the coils and No 5 still was the issue so I think it will be a mechanical issue as it head gasket or valve.

On a 100km round trip to my brothers on Sunday night it returned 10.1 L/100 with me testing the power a few times - when cruising at 100 you would not know it has a problem. Normally a burnt valve or head gasket would not run sweet at 100kph.

[88GreenVN]

Compression test showed up as

1-160
3-130
5-135
2-160
4-100
6-130

[azzfox]

Damn, fair difference from highest to lowest. 100 is also the minimum spec for the V6.

[delcowizzid]

should of got them to add oil to the cylinders and retest to make sure its rings ide say its rings the front 2 are higher cause they are allways colder being in the front of the engine so less wear.could also be 2 blown head gaskets between the rear cylinders on both banks but im sure it would run a lot worse if that was the case

[88GreenVN]

should of got them to add oil to the cylinders and retest to make sure its rings ide say its rings the front 2 are higher cause they are allways colder being in the front of the engine so less wear.could also be 2 blown head gaskets between the rear cylinders on both banks but im sure it would run a lot worse if that was the case

Ran out of time to do the oil test - but also concluded that if it was blown head gaskets it would run alot worse. Car is not using oil. I've only added a cup full in the 12 months I've had it. And that probably leaked out..

On the express way @ 100 it's as smooth as. Nothing rattles at all. No shakes. Come to a stop at the lights and it gets up a real good brurp brurp brurp. Sounds like a really wild cam and the whole car gets up a bit of a shake n rattle. (new engine and tranny mounts a few months ago).

So next on the list is a set of injectors.

[88GreenVN]

Damn, fair difference from highest to lowest. 100 is also the minimum spec for the V6.

Hmmm yes 100 is low - and 160 I thought was very high too.

But a worn compression ring should not make the car run so poorly at idle. - should it?

[Not_An_Abba_Fan]

No. Does it tick at all? Maybe you have a sticky lifter. The missus VN is doing that and while it ticks it misses. But it clears itself after a couple of minutes.

Just had another thought, has the bellmouth been removed?

[delcowizzid]

its VN so it wouldnt of ever had one

[Not_An_Abba_Fan]

Series 2 had one, but his is a series 1 I think.

[88GreenVN]

No. Does it tick at all? Maybe you have a sticky lifter. The missus VN is doing that and while it ticks it misses. But it clears itself after a couple of minutes.

Just had another thought, has the bellmouth been removed?

No I cant hear a lifter noise. (the wagon when using shell oil would clack on start up after about 5000 k's - which would tell me it's time for new oil)

So no lifter clack type noise at all.

It is more of a lumpy cam type idle when in gear stopped at the lights. No stalling or miss fire under load. Takes off like a rocket if you put your foot into it.

It has me buggered.

Bellmouth????? I have not checked that at all? Hmmmm should have a look tonight

[norman]

Does it do it out of gear at the lights (N or P)? if not could be your converter not disengaging the gear properly.

[88GreenVN]

Does it do it out of gear at the lights (N or P)? if not could be your converter not disengaging the gear properly.

Yes it has the miss out of gear - just more noticable when in gear.

I replaced the injectors last night with a second hand set - but no change. I'll try a DFI unit next see if that helps. If you bring the idle up in neutral it has "fluttery miss".

I dont know if the single coil/DFI units can die on one set or not. Swapping the coils over would not help as it would just move the miss to another set of cylinders......

[Not_An_Abba_Fan]

I'm wondering whether it is just the way it runs at idle. If it runs fine under power and you are getting reasonable economy then I wouldn't be too stressed about it.

Do you have a timing light? Hook it up to each lead in turn and see if you are getting constant spark.

[88GreenVN]

I'm wondering whether it is just the way it runs at idle. If it runs fine under power and you are getting reasonable economy then I wouldn't be too stressed about it.

Do you have a timing light? Hook it up to each lead in turn and see if you are getting constant spark.

No timing light

The car has had a sort of miss for the year I've had it - it's only just in the past few weeks it become very noticable as the car is now being used on longer trips down the expressway (30 k trip) at mostly 100kph. Prior to that 70 was the max speed on it's trips.

I figure what ever is the problem longer faster deiving is making it worse - at some point what ever it is will break no doubt and require a tow.......

Next trip to the mechanic's will be to test the spar out of the coils/DFI.

[88GreenVN]

Update:

Had Davecunno have a squizz at the 89 green beast last night - swapped over the MAP sensor with my V8 unit and that made it run a bit better. Checked over all the spark and looked to be OK. Looking at the fuel reg and filter tonight (got a filter from Sprints on the way to work today).

Thanks Dave for your help. (nice Pickup in the VN 5 speed too).

[greenfoam]

Have you tried changing the injector on number 5? with another? also look for a broken spring on 5, infact run it without the rocker covers and try see if both valves are working right, could be bent pushrod, broken spring, dud injector (if it's not electrical)

[Pub247]

I dont think itd be a bent pushrod they can make a hell of a racket. and it if wasnt bad itd stil clatter a bit

[88GreenVN]

Got the car back from a fuel line rebuild today and the mechanic said the most likely problem was a worn cam. So it will stay like it for some time (I hope)

When I replaced the fuel filter last night the lines that go back to the tank were in about 20 bits. The top of the tank had lots of dirt on it that was very wet with petrol. So this has not helped the economy at all. Every time the car was turned off it would dump a small amount of petrol onto the top of the tank I'm guessing.