Replacing Intake Manifold Gasket

[xp_wannabe]

My AU2 XR6 Ute (VCT) has developed a rough idle and a bad miss just off idel / under load. Clears out fine with a few revs. It is also hard to start when cold.

I have replaced coil, leads and plugs (leads and plugs twice thinking they were faulty) and had the injectors cleaned, to no avail.

I am thinking it is the intake manifold gasket, as I have read on here that it is quite common.

I have sprayed aerostart all around the intake manifold with the engine idling, but didn't notice any change. Could the gasket still be faulty?

Is there a good thread on here showing how to replace the gasket? Is it a big job?

Thanks, Mark

[Mr Hardware]

when was the last time you changed your fuel filter?

[xp_wannabe]

Originally Posted by Mr Hardware

when was the last time you changed your fuel filter?

About 20,000km ago. I haven't checked fuel pressure either, waiting on a mate with the equipment to give me a hand. Could it be the fuel pump?

[TheSly1]

Changing the Intake Manifold gasket isnt that big of a job, you just need the right tools to make it easier.

Ratchet spanners will make things a ******** easier, also a stubby ratchet spanner on the back bolts up near the coil pack i think it was, is REALLY recommended.

[GK]

If the areostart made no difference, then I'd guess it's not that gasket.

Just use a 10mm and tighten (gently) all the bolts on the manifold you can get to anyway. Good insurance.

Have you cleaned the IAC?

Cleaning IAC/ISC Valve

http://www.fordforums.com.au/showpos...9&postcount=43


GK

[xp_wannabe]

The last 3 mechanics I have spoken to have all told me to compression test the engine, because they reckon it could be the head gasket (even though it doesnt get hot and doesnt use water), so, I have just finished doing just that.

The compression tester I was using is meant to be used on motorbikes, and I couldnt tighten it down properly in the plug holes. Anyway, here is what I got:

Cyl 1: 200psi
Cyl 2: 210psi
Cyl 3: 190psi
Cyl 4: 180psi
Cyl 5: 180psi
Cyl 6: 210psi

On cyls 4 & 5, the compression was still going up when we stopped cranking, but we had to stop because the threads were coming out.

I think the head gasket is fine.

I am convinced I can hear a loud hiss coming from the intake manifold gasket at cyl 5 on idle, that goes away as you rev it.

I will clean the IAC valve, and replace the fuel filter. If that doesnt work, think im just gonna hook in and replace the intake gasket.

Thoughts?

[GK]

Originally Posted by xp_wannabe

I will clean the IAC valve, and replace the fuel filter. If that doesnt work, think im just gonna hook in and replace the intake gasket.

Thoughts?

Won't hurt and they are both simple enough to do. The fuel filter nuts will be darn tight I'm tipping!

Then go for the gasket as you've said.

Keep us posted.

GK

[xp_wannabe]

Why do you say that GK? I have replaced it regularly, last time was about 20000km ago.

[GK]

I thought I was going to snap something last time I undid the fuel filter! LOL!

Thank God it wasn't my gut!

GK

[xp_wannabe]

Some mates and I got stuck in and replaced the intake manifold gasket on Saturday arve, ute purrs like a kitten again now...

All the bolts holding the inlet manifold on were loose, and the old gasket just crumbled and fell away.

Took us about 2 hours all up, but if the engine wasn't hot, and we didnt drink so many beers, it wouldve been alot quicker!

Thanks for all the help guys.

[Maka]

Well done on resolving the miss & rough idle it can be a pita lol! i went through all the usual stuff/money trying to sort out a slight miss at idle in my i6 intech.There are ways to check which parts are faulty without spending money on parts you dont need, lol! I learned alot through that period thats for sure!

cheers,Maka

[Blr]

Hi all I just replaced the intake manifold gasket on our ford au straight 6 and it was running like a dream. Took it for a good drive yesterday with out a hitch. The wife started it up this morning and it was running rough like its starving or not firing right. Any idears anyone?

[Maka]

Did you reset the battery? The ecu probably needs relearning.

cheer's Maka

[Blr]

Thanks MAKA I will give it a go. Hopefully that's all it is.
Seems strange that it ran so sweetly till it sat over night and then the problem presented itself. I'll let u know how I go.

[xp_wannabe]

Go over the bolts again, some of them may have worked loose after the heat cycle

[Blr]

So I reset the battery and went over the bolts. No change in problem. Car dose seem to run a bit better when idling until I take off and it seems like it's got a miss in one of the cylinders.

[Maka]

Hi there, the ecu will take about a week or two to relearn. If not better after the relearn period, give it a full service & go from there. Get a ecu scan & see what codes are about. Good luck!

cheer's, Maka

[DA_TERMINATOR]

Originally Posted by xp_wannabe

My AU2 XR6 Ute (VCT) has developed a rough idle and a bad miss just off idel / under load. Clears out fine with a few revs. It is also hard to start when cold.

I have replaced coil, leads and plugs (leads and plugs twice thinking they were faulty) and had the injectors cleaned, to no avail.

I am thinking it is the intake manifold gasket, as I have read on here that it is quite common.

I have sprayed aerostart all around the intake manifold with the engine idling, but didn't notice any change. Could the gasket still be faulty?

Is there a good thread on here showing how to replace the gasket? Is it a big job?

Thanks, Mark

How did you go with the gasket replacement.