newbie with a mr2 rev3 turbo powered lexus is 200

[chri5]

I was told the gt4 although being the same engine ws slightly different and may not work???s

[toxo]

The coolant layout is a bit different but that's all custom on your engine anyway...

[chri5]

Yeah for some reason it's blowing the oe thermostat out. So they put inline thermostat in.
Could this by any chance be connected???s

[toxo]

My understanding of that was that the piece of the thermostat housing that exits to the radiator has been altered by having a pipe welded onto it. When they welded the pipe onto it the thermostat housing has warped, so the thermostat does not seal inside the housing anymore. This allows cold coolant to flow past it to the radiator when it shouldn't, which is why the OE thermostat was removed and replaced with an inline one.

[chri5]

Well that's more of an understanding than the original owner told me!!!
No welded pipes was ever mentioned.
So with this in mind if I got a new housing and thermostat would it cure this problem???
Would certainly look better than having that inline thermostat

[toxo]

It would cure the thermostat problem. However it would create a new problem in that the outlet from the thermostat housing wouldn't point anywhere near the radiator inlet, which is why it was modified in the first place.

Also there's no indication that particular modification is anything to do with your current problem. The fact that the head bolts were loose when you came to remove the head would be a far bigger contributing factor.

[chri5]

That's very true toxo.
I'll deal with thermostat at a later date if I keep the car.

Just another point regarding cylinders filled with water.
The bolt holes are also filled with water.
Obviously when the bolts are in place they can't fill up.
So does this conclude that the water is from when I parted the head???

[Chris]

It's turned down, I think 1BAR? Unless Chri5 has turned it back up to 1.2

TBH, considering you found the head bolts were loose, I would throw it all back together to the correct torques and tolerances and see if it works Loose bolts could cause the head to lift and then water could get all sorts of places without any head gasket failure.

Overheating can cause the bolts to be stretched when the head/block expands. When the lot cools again, the bolts appear loose as they are now a little longer. Seen this alot on Supercharged V8's. I'd not just hope for the best, as said, check the cylinder walls. Have you any pics of the HG? Did you drain the coolant before stripping the engine?

Cool car by the way

[toxo]

Overheating can cause the bolts to be stretched when the head/block expands. When the lot cools again, the bolts appear loose as they are now a little longer. Seen this alot on Supercharged V8's.

I thought that, but as only some were loose, if that were to happen from stretching through expansion then there's been some VERY uneven expansion through the head and it'd be warped to hell, wouldn't it?

[Chris]

It might be warped to hell matey, until it's pressure checked and flat edge checked, I'd presume thermal expansion has cause the bolts to stretch.

The last car I saw like that, the middle 4 bolts I could take out with my fingers! The outer set were still as tight as when it was built. That was caused by coolant loss through a split return pipe. The HG was perfect! Just purely down to excessive heat.

[chri5]

It might be warped to hell matey, until it's pressure checked and flat edge checked, I'd presume thermal expansion has cause the bolts to stretch.

The last car I saw like that, the middle 4 bolts I could take out with my fingers! The outer set were still as tight as when it was built. That was caused by coolant loss through a split return pipe. The HG was perfect! Just purely down to excessive heat.

it was the middle bolts that were loose.
Wouldn't say undoable by hand but no real effort for the ratchet.
They were also on the exhaust side if that makes a difference???

[bobhatton]

To remove the pistons you only need to take the sump off undo each rod bolt and push the piston out the top of the bore. You have done all the hard work taking the head off, the piston part is easy now.

With the stat, it cannot be removed because as it opens up to the rad it shuts off the bypass, so if the stat is missing most of the water will go round the bypass and over heat the engine and by the sounds of it that has been your problem.

If the block is damaged you can use any year of block, it does not have to be a Rev 3.

If you need any help PM me and I will give you my phone number.

Bob

[monkeyra]

Rebuilt May 2009 and already blown up?

[chri5]

Bob that's very nice of you thank you. Not sure where your located but I am in croydon.

So to check the pistons is easy then???
Always thought it was hard.

What's the chances of block damage???
Am I just creating more work an expense???

You say the stat shuts off to create a by pass???
So this inline thermostat isn't doing anything then???

[chri5]

Rebuilt May 2009 and already blown up?

mate don't lol
if you also notice I've only owned it a week.
Apparently it'd done around 6000 perfect miles.

[bobhatton]

If you do not check the pistons and there is a problem you will only find it when you run the engine again, then it all has to come apart again.

There is no cost in taking the pistons out and checking them apart from getting a piston ring compressor to help you to put them back in the bores.

You must have the stock stat fitted, you must never run a 3sgte engine without one.

I am in Cornwall so a bit far away or I would have come round and helped you sort the problem out, but I can still talk you through it.
Bob

[Chris]

There's every chance it's a split block....And yes it'll just get more expensive.

A second hand good long block might be the way forward, or sell the car to me as it is, and I'll build a forged one with sleaves for it

[chri5]

If you do not check the pistons and there is a problem you will only find it when you run the engine again, then it all has to come apart again.

There is no cost in taking the pistons out and checking them apart from getting a piston ring compressor to help you to put them back in the bores.

You must have the stock stat fitted, you must never run a 3sgte engine without one.

I am in Cornwall so a bit far away or I would have come round and helped you sort the problem out, but I can still talk you through it.
Bob

ok I'll give that a go at the weekend
won't the pistons go back without the compressor???

[Chris]

Not without possible damage mate, ring compressor are very cheap! Go buy one

[chri5]

There's every chance it's a split block....And yes it'll just get more expensive.

A second hand good long block might be the way forward, or sell the car to me as it is, and I'll build a forged one with sleaves for it

so worse case scenario I need a new block.
How much will that cost me???

How much you offering lol
don't really wanna sell it tbh but I've really been put off with it.