MR2 Roadster - A Tale Of Woe, Maybe...

[Willhire89]

My '03 car had a head gasket go completely out of the blue and it had pretty much no compression across all four cylinders. It would spin over as if there were no plugs in it.

[Martin350]

AW111 said:

Checked the head gasket yet?

The leak down test would have revealed a head gasket blow into a combustion chamber, no signs of a big leak here.

Vitorio said:

Interesting read, it is somewhat baffling that all these modern emission gizmos make engines so fragile and just overcomplicated. I shudder to think about how maintaining one's own car will be once all the simpler stuff is on the scrapyard.

I hope it turns out to be an easy fix, but its looking like a head-off job right now from my point of view

Yes, I agree, it is getting harder to maintain modern cars, not to mention costly when electronic stuff needs replacing.
Thanks.
I'm suspecting it might end up with the head off too, but we'll see...

james_gt3rs said:

Could it have just been a loose spark plug making the noise? I don't remember reading many head gasket posts when I owned mine.

No, I've not heard of head gasket issues with this engine, but it can't be ruled out just yet.

And yes, the bit of broken plug could have made a knocking noise.
I have found no trace of any bits of the plug!


When I get home from work this evening I'm going to try and sort out a couple of knackered studs in the exhaust manifold and give it a thorough clean out, then have a quick look at the other three big end shells and measure the big end cap bolts (there is a tolerence for reusing them).

[Paddymcc]

Seems like you have had some unfortunate luck!

maybe an ideal excuse to stick in a 2zz engine?

[james_gt3rs]

Timing chain tensioner gone?

[Martin350]

Paddymcc said:

Seems like you have had some unfortunate luck!

maybe an ideal excuse to stick in a 2zz engine?

It does seem rather unlucky at the moment, I just want to find out exactly what has happened!

And yes, a 2zz or a Camry V6 did cross my mind, but I don't really want to spend the sort of money needed for the conversion on this car.

james_gt3rs said:

Timing chain tensioner gone?

Thanks for the suggestion, but I've heard one of these engines with a worn chain and sprockets running, and it's a very different noise to mine.

[Roo]

Should be good fun once you've sorted it out.

Martin350 said:

I have a very good mate who is a car painter who will help me sort a few bits out

Is he good? I might be needing the bonnet on my car doing again.

[Martin350]

Hi mate.
Yeah, should be ok if we get some more of this fine weather!

He is good, but he's currently working for himself doing the smart repair thing.
That's fine for tidying a £922 MR2 bumper corner, but if you're looking for a full bonnet repaint then he might be reluctant.

I can ask him for you though.

[Roo]

If you don't mind. It would be the entire bonnet.

[James 33]

Could it not be as simple as the plug failing and the death rattle you can hear just be the end of the plug bouncing around inside the combustion chamber?

[Martin350]

Roo said:

If you don't mind. It would be the entire bonnet.

Ok, I'll ask.
It's for the Mustang, I assume?

[Martin350]

James 33 said:

Could it not be as simple as the plug failing and the death rattle you can hear just be the end of the plug bouncing around inside the combustion chamber?

That crossed my mind too, but I've had a good look in there with a borescope and didn't see anything unusual.

[RYH64E]

The missing part of the spark plug must have gone somewhere!

[Martin350]

Indeed!

I did keep an eye out for it when I smashed the pre-cats out, but nope!

I'm hoping it's not embedded in the head or something!

[Martin350]

The weather scuppered my plans this evening, but inside the (tiny) garage I sorted out a few things, new manifold studs in the head, drilled and tapped a snapped cam cover bolt in the head and repaired a few threads / studs in the exhaust manifold.
So it wasn't a waste of time.

[Markbarry1977]

Bookmarked. I just want to know where the sodding spark plug top has gone.

[Martin350]

Me too!

[liner33]

Only one place the spark plug tip as gone , you can burn the metal ends of the plug but not the ceramic so thats gone through the motor.

Give us more detail on how you did the leak down test ?

Heads gotta come off i reckon

[Martin350]

Leak down test was done the only way I'm aware of - tdc on firing stroke so valves shut and compressed air let into the cylinder.
I must admit I didn't note the readings, I was mostly looking for consistency across the cylinders, which wasn't bad.

After looking at images online I've realised how little I could see of the pistons with the borescope, so head off it could well be.

I might get the other big end caps off tonight for a quick look, seeing as the sump is still off and it only takes a few minutes.

[steveo3002]

have you ran it with new plugs in? worth a try before the head comes off?

[Martin350]

I'm in two minds about that, but I am tempted to try it, I've got a new set of plugs...