[jdk81]

No thermostat can and does cause issues, a thermo stat stuck open is nearly as bad.
For a few reasons.

The coolant will follow the path of least resistance (electronic-hydraulic analogy)
Secondary lines, such as the heater core and line up to the throttle body IAC valve or carby (which ever applies) will not see the correct flow rate.
Areas within the head, block, and manifolds etc will also experience a huge variation in flow.
Some areas will get stupid hot as the water doesn't move very much through them.

The coolant will also flow at full speed
Due to the surface area of the radiator, flow rate (cm^3/cm^2 to get the velocity) I wouldn't expect the speed through the radiator to actually be the problem.
Turbulent flow, cavitation and bypassing section is the issue.
While the water is moving faster and mixing better (in certain areas), where there is cavitation there is less surface area in contact with the fluid.
Some areas will be more static, thus they will cool slower too.
These factors will be a big part of the reason why the cooling capacity is reduced.

From experience
It'll run poorly when cold, take ages to warm up, and when its warm, the heater core and IAC wont work properly.
You'll freeze in winter and it'll idle a little lumpy.
When the car is under load, and rpm is high it can get stupid hot.

I cant be bothered debating other stuff at this point in time.

[murcod]

TEKNO wrote:

So first thing this morning i checked the coolant before starting the engine and the reservoir bottle was brimming and I could see the core again in the radiator so i simply topped it back up then went and got a new radiator cap and also rang my mechanic who said that yes a rad cap could be the fault BUT if its still playing up in a few days bring it in and we'll do a TK test which test's for exhaust gasses in the coolant which will then confirm if its a head gasket or not so that is what I shall be doing. Its only $25 to do the test so why not I figure!
So its obviously pushing the coolant out into the res bottle but not sucking it back again so hopefully just the rad cap????
We'll see.

Check that there are no air leaks/ cracked hoses between the radiator pressure release outlet and the submersed hose end in overflow bottle coolant- that could also cause no coolant to be sucked back in.

Don't know if I mentioned it earlier, but have you tried squeezing the top or bottom coolant hose when the engine is warm? (Be careful not to burn yourself of course....) They should be pressurised and hard to squeeze (ie. your cap should be holding pressure with a hot engine.)

PS: if it does turn out to be more sinister than a radiator cap, give this stuff a go: https://www.conbear.com.au/Product/info/10661092

[TEKNO]

So after 2 rad caps because I thought the first one I bought was faulty my mechanic did a TEKAY test yesterday and it showed all clear,no head probs but today I went for along drive about 100ks return and I let the car sit for about half an hour when I got home and then went out and checked again and same shit different day,res full and I can see the core in the radiator so clearly NOT the rad cap and yes I did squeeze the top and bottom hoses which are holding pressure nicely so I rang my mechanic who was as surprised as I was and we both said lets try some Chemiweld or something like that or perhaps like the one mentioned above by murcod as it may be starting out a small problem with the head gasket but not enough to show on the TEKAY test? faaaark me its proving hard to find the bugger...everything else looks great,no leaks,no overheating,runs like a dream...stuff knows so additive it is for now.

[MrRocky]

Thermostat

[MrRocky]

If your mechanic is suggesting chemiweld i think its time for you to find a new mechanic

[TEKNO]

Me thinks its time for a second opinion so tomorrow morning im heading down to the dyno shop that did my 1.8 install as he has a different way of testing for problematic head gaskets and I will post again when I get home from there with his results.
cioa for now

[Joe]

MrRocky wrote:

If your mechanic is suggesting chemiweld i think its time for you to find a new mechanic

X2

[atari4x4]

Joe wrote:

MrRocky wrote:

If your mechanic is suggesting chemiweld i think its time for you to find a new mechanic

X2

+1

I'm guessing Dan` is his current mechanic.

[TEKNO]

^^^Yep I totally agree and I gotta say that I was very disappointed with his attitude today on the phone as he was rather short with me after I said that your Teekay test didn't work, and note I wasn't rude or harsh merely stating there's still a problem clearly. I go to them for convenience as they are close whereas the specialised dyno shop is approx 60 ks away but I have decided to go there tomorrow now to try and find an answer.Some people rely on mechanics as they have a limited mechanical knowledge and when they don't seem to have the time to talk or suggest things that don't ad up then one has to question why??? Dammit

[jdk81]

Drive further, it is only 60kms.
What do the plugs look like?
A cracked block/head can sometimes be a mofo to determine.
Good luck.

And i wonder
How long until mrrocky types "thermostat" again?
Will it be in capitals?
Will it be written slowly so its easy to understand?
Will it be the solution?

Only time will tell.

[THE_DICTATOR]

Take the cap off, fill the radiator and start the motor. See what happens. If it doesn't erupt out the top of the rad when revved then do a pressure test. Buy your own kit as it is cheaper then paying someone to do the test

[TEKNO]

So I went to the good blokes at the dyno shop and after doing a test in which he stops the fuel pump working so the engine cranks freely without starting and puts a funnel in the top of the rad designed for this purpose and fills it with water and upon cranking we could plainly see lots and lots of bubbles so yes most definitely head gasket or cracked head,sigh.so it's booked in for next Tuesday to get it fixed,what a shit,there goes the savings again.
But hey at least I know now and I thank you all for your input regarding this.
So is head gaskets common on these motors or is this a case of shit happens?

[atari4x4]

don't the m series motors have a habit of dropping the cylinder sleeves once hot?

[MrRocky]

Prob cheaper to upgrade and get low km m15 ???
Guy here in w.a. got low km one shipped from suzi wreckers in qld for $500

[watermouse]

Tekno already has the 1.8

[alien]

TEKNO wrote:

So after 2 rad caps because I thought the first one I bought was faulty my mechanic did a TEKAY test yesterday and it showed all clear,no head probs but today I went for along drive about 100ks return and I let the car sit for about half an hour when I got home and then went out and checked again and same shit different day,res full and I can see the core in the radiator so clearly NOT the rad cap and yes I did squeeze the top and bottom hoses which are holding pressure nicely so I rang my mechanic who was as surprised as I was and we both said lets try some Chemiweld or something like that or perhaps like the one mentioned above by murcod as it may be starting out a small problem with the head gasket but not enough to show on the TEKAY test? faaaark me its proving hard to find the bugger...everything else looks great,no leaks,no overheating,runs like a dream...stuff knows so additive it is for now.

My sierra (G16 block) has done this TWICE! both times the gasket blew between cyl 2 & 3 via an exhaust port. Have had the thing machined the last time it happened to try avoid it happening again, again. There were no physical signs on the gasket either, just a dried up coolant line on the block where you could see the path it was taking.

It passed TEKAY tests, compression tests etc etc same as yours. The only other noticeable thing was the smell of petrol and a residue build up in the overflow bottle over time. I drove mine the first time for about 6 months just constantly topping up the rad, so the build up was very obvious near the end. The second time it happened i knew what it was almost straight away, so just drove it until it was due for a service.

I'd definitely recommend if you replace the gasket to have the head and block checked and maybe take a few thou off just to be super sure.

[murcod]

murcod wrote:

PS: if it does turn out to be more sinister than a radiator cap, give this stuff a go: https://www.conbear.com.au/Product/info/10661092

I agree it's on the dodgy side, but I'd give the above product a go before shelling out lots of money for the engine to be stripped down. It's supposed to be a permanent fix and I've read lots of good reports about it.

[britvit]

alien wrote:

TEKNO wrote:

So after 2 rad caps because I thought the first one I bought was faulty my mechanic did a TEKAY test yesterday and it showed all clear,no head probs but today I went for along drive about 100ks return and I let the car sit for about half an hour when I got home and then went out and checked again and same shit different day,res full and I can see the core in the radiator so clearly NOT the rad cap and yes I did squeeze the top and bottom hoses which are holding pressure nicely so I rang my mechanic who was as surprised as I was and we both said lets try some Chemiweld or something like that or perhaps like the one mentioned above by murcod as it may be starting out a small problem with the head gasket but not enough to show on the TEKAY test? faaaark me its proving hard to find the bugger...everything else looks great,no leaks,no overheating,runs like a dream...stuff knows so additive it is for now.

My sierra (G16 block) has done this TWICE! both times the gasket blew between cyl 2 & 3 via an exhaust port. Have had the thing machined the last time it happened to try avoid it happening again, again. There were no physical signs on the gasket either, just a dried up coolant line on the block where you could see the path it was taking.

It passed TEKAY tests, compression tests etc etc same as yours. The only other noticeable thing was the smell of petrol and a residue build up in the overflow bottle over time. I drove mine the first time for about 6 months just constantly topping up the rad, so the build up was very obvious near the end. The second time it happened i knew what it was almost straight away, so just drove it until it was due for a service.

I'd definitely recommend if you replace the gasket to have the head and block checked and maybe take a few thou off just to be super sure.

Maybe time to upgrade to a MLS gasket?

murcod wrote:

murcod wrote:

PS: if it does turn out to be more sinister than a radiator cap, give this stuff a go: https://www.conbear.com.au/Product/info/10661092

I agree it's on the dodgy side, but I'd give the above product a go before shelling out lots of money for the engine to be stripped down. It's supposed to be a permanent fix and I've read lots of good reports about it.

I used a similar product on a motor that had a cracked block/head, the leak was so bad coolant would drip on to the ground without the motor running. The product more or less stopped the leak. It also totally blocked the throttle body and would block the tube to the overflow bottle, I ran it for 2 years like that. I'd only use it again on a junk motor just to get by.

[TEKNO]

So after having Jim back for a week now I can report it is fixed and no more coolant loss.Also it was a MLS gasket already(factory one perhaps???) and yes a MLS went back in.
Another bonus was that I wasnt entirely happy with the tune on the XEDE ECU so while it was there I had him retune it because it was pinging very occasionally before so now thats been done jim is now making 69kw ATW whereas before it was making 64kw ATW....could the pinging beforehand have contributed to the blown head gasket? I asked this question and was told because it was so minor that he doubted it.
Whats your thoughts peoples?
tanku

[britvit]

Glad you got it fixed TEKNO, my comment about the MLS gasket was aimed at allien. 69KW atw is pretty good, are you running it on 98 fuel?

[TEKNO]

Well the sticker in the fuel flap reads 95 or higher so most times yes I do run 98 but occasionally I will use 95 and I have noticed no difference between the two variants,and yes jim certainly goes well now and quite responsive.

[murcod]

TEKNO wrote:

could the pinging beforehand have contributed to the blown head gasket?

It certainly would have. http://aftermarket.federalmogul.com/en- ... nition.pdf