well its been 30mins since i did the block test kit and guess what?

 

 

it stayed blue

 

this is the kit i got

 

http://www.uktools.com/block-tester-p-12508.html

 

Tests in seconds for:

Cracked Blocks

Leaky Gaskets

Cracked Heads

Warped Heads

When Fluid Turns From BLUE TO YELLOW Combustion Leak is Present.

 

well its still blue...

 

so what on earth is causing my overheating issue.

 

The car has only ever reached 127degrees once. all my testing I've never let the car get higher than 105 as I've shut the engine down once it approaches 100c

 

So im now stumped

 

But im glad its not a blown head gasket.

I think that is exactly the problem. Have you tried the washing powder trick yet? If you do, can you video it please :D I reckon it'll work though, as others have said, it's got the same active ingredient as the rad flush, just a little foamier, which provided you have the rad cap off, is more than likely fine and will probably help more than the rad flush would.

I think that is exactly the problem. Have you tried the washing powder trick yet? If you do, can you video it please :D I reckon it'll work though, as others have said, it's got the same active ingredient as the rad flush, just a little foamier, which provided you have the rad cap off, is more than likely fine and will probably help more than the rad flush would.

 

i dont care how many people say it works, im not sticking suds in my engine. next thing you know the mrs will be down at it using it as a fecking washing machine, id have more problems then when socks start going missing. :lol:

Go on, get it in there. Anyone else dare to do it first just to prove it to him that it works and is ok? BAGSY NOT ME!

BAGSY NOT ME!

 

Kind of says it all..

Kind of says it all..

 

;)

Okay, i've run it by the old geezer and we discussed what his GTO has been known to do.

 

His also can run fine then randomly overheat, what we found it to be on his is a poorly seeling radiator cap, it seems a small amount of gunk/sludge/grime, occasionally comes out of the rad and gets under the cap seal and it can't pressurise properly hence the overheating is caused.

 

Would explain why yours was fine for a 2 hour drive, check under the rad cap for sludge/crud around where it seals, if there is any just give it a clean and put it back on and you should be right, i'd be replacing the rad though as it is the most likely source of afore mentioned gunk.

squirrels.......i blame the squirrels

Okay, i've run it by the old geezer and we discussed what his GTO has been known to do.

 

His also can run fine then randomly overheat, what we found it to be on his is a poorly seeling radiator cap, it seems a small amount of gunk/sludge/grime, occasionally comes out of the rad and gets under the cap seal and it can't pressurise properly hence the overheating is caused.

 

Would explain why yours was fine for a 2 hour drive, check under the rad cap for sludge/crud around where it seals, if there is any just give it a clean and put it back on and you should be right, i'd be replacing the rad though as it is the most likely source of afore mentioned gunk.

 

ive changed the rad cap twice, second time was for a brand spankers one, rad filler next is clean as a whistle.

ive changed the rad cap twice, second time was for a brand spankers one, rad filler next is clean as a whistle.

 

Yeah we changed cap on GTO as well and still have to give it a wipe occasionally its bugger all but just enough for it not to seal.

 

Can't ya just ask a neighbour if you can use thier hose? find somebody with a long one :D

 

The water going back into the resi bottle really really does scream air lock though, i know you know the procedure but uhhh you are bleeding it on dead level ground right?

Yeah we changed cap on GTO as well and still have to give it a wipe occasionally its bugger all but just enough for it not to seal.

 

Can't ya just ask a neighbour if you can use thier hose? find somebody with a long one :D

 

The water going back into the resi bottle really really does scream air lock though, i know you know the procedure but uhhh you are bleeding it on dead level ground right?

 

the parking spot its on raises slightly towards the front of the car, but i always bleed the system with the nose raised anyway.

the parking spot its on raises slightly towards the front of the car, but i always bleed the system with the nose raised anyway.

 

Hmm, good way to get some air caught though.

 

Ah well check ya rad out first once thats eliminted all that can really be left is the air lock.

 

If i have any more bright ideas you'll be the first to know once i discuss it with myself and decide it must be right.

I think the general conscientious is,

if you have the front slightly raised, the air will naturally be driven to the highest point, ideally the radiator filler neck.

Mrs's dads got hold of the lads at santa pod, so got a flat bed on the way to get the car up to his, going to strip the front of the engine and get a high pressure hose in it and give it a good effing flush out and go from there.

I think the general conscientious is,

if you have the front slightly raised, the air will naturally be driven to the highest point, ideally the radiator filler neck.

 

Yes but it also gets trapped in places in the galleries inside the engine and in the heater matrix.

 

The engine is designed to be bled level.

Mrs's dads got hold of the lads at santa pod, so got a flat bed on the way to get the car up to his, going to strip the front of the engine and get a high pressure hose in it and give it a good effing flush out and go from there.

 

 

Hope that fixes it! Use a good flushing product as well. These do help in "loosening" the crap in the system.

My final two penneth here would be to take the Stat out and put some Rad flush in, bleed, as before, and go for a gentle run.

 

Come home, let it cool, drop coolant (some into a bowl and use your test kit again?)

 

Repeat above.

 

repeat again, but put a working stat in (test in a pan first) then refil with 50/50 antifreeze mix? Are you/have you used/using any (even cheap) in all that you've done before? Remember adding coolant mix will lower the boiling point of your coolant further (and keep the system clean!)

 

Been bleeding a VW camper i bought for the last couple of weeks after doing what i've described above...(It's 25 years old and the Z is 18 now so you'll be surprised what comes out if it's not been flushed before in an older car!)...I have seen my temp drop on the van now from 3/4 (with air in system) to just above mid way last weekend after two more bleed sessions... Another session tomorrow to get more coolant in and hopefully drop my temp to below half way...I'm also using decent comma additive (antifreeze) and not cheap stuff to lower the boiling point...Worth a read if you have 5 mins and not too far off the proceedure i've followed on the Z...

 

http://www.brick-yard.co.uk/forum/bleeding-the-cooling-system_topic29710.html

 

only exception is i have raised the nose on the Z on a hill out of my estate when bleeding the car with teh temp on 40 and teh fan on full... I also dropped the nose on the camper (after bleeding rad) as the header tank is in the back! Z can also be done in one hit yourself with no need of an assistant so worth a couple more hits with 2 x £3 rad flush?!

 

Best of luck..

 

(also PM Bump!)

Edited December 10, 201114 yr by TubZ

I know I'm splitting hairs, but it is kinda important, you mean raising the boiling point of the coolant. Anti-Freeze boils at a higher temperature and mixes with the water to form a new substance with a higher boiling point than just water, but lower than anti-freeze itself amd a lower freezing point than just water.

Yes but it also gets trapped in places in the galleries inside the engine and in the heater matrix.

 

The engine is designed to be bled level.

 

That's why it's important to rev it a little at a constant above 2K and push the air to the top with the rad cap off and bleed screw open...

I know I'm splitting hairs, but it is kinda important, you mean raising the boiling point of the coolant. Anti-Freeze boils at a higher temperature and mixes with the water to form a new substance with a higher boiling point than just water, but lower than anti-freeze itself amd a lower freezing point than just water.

 

Split away! Should have said 'raise' not 'lower' but you get what i mean...The cars are designed to be run with Antifreeze/Coolant mix (not sure the exact mix, but will revert to those with higher knowledge) for temps to be read off the 'New Substance' NOT pure water....

 

From the post in the Dubs forums..

 

You heat water, it expands. (Heat a 'new substance' -Less expansion!)

You pressurise water, it raise it's boiling point.

You heat something in a confined space and you raise it's pressure.

You can compress a gas, you can't compress a fluid (much)

Water finds it's own level.

Edited December 10, 201114 yr by TubZ

Well Santa pod flat bed arrived, always nice to at least have the zed on a truck with santa pod down the side rather than looking just like a recovery truck lol

 

 

the santa pod dragster

 

 

ideas crossed our mind of fitting this in it lol

 

right anyway, got the car there, had some help from one of the guys in the Lotus F1 team who works on the gearboxes who popped along with some fancy equipment to accurately measure engine temperatures.

 

the low down is, i managed to drive the car home with the temp reaching a scorching 85 degrees. we gave the engine a really thorougher flush and you wouldn't believe the amount of crap we managed to blast out of the heater matrix. refilled the system and started the engine, with some technical gadgetry we found out what was going on, the temp sender on the main top water pipe was reading the temp as 98 degrees, about the same time as i turn the engine off due to not wanting it to over heat.

 

The temperature equipment was showing the engine at a poultry 58, which is not enough to open the thermostat, we decided to let it get hotter using the equipment to monitor the engine and pipe temperatures, soon as the engine got 73 degrees the thermostat opened and the radiator just emptied, it took another 3 liters of antifreeze :blink: i got hot air in the cabin and the temp on conzults rocketed from 109 to 84 degrees, we left it idling and kept topping up as necessary, another liter later and a good 45 mins, the car was stable on 84degrees, not only on consults but also on the temp equipment. at this point it was time for a test drive, so took it for a quick spin around the block, temp raised to 85 but no higher, still had hot air, got it back let it idle and it settled back down to 84.

 

So looks like my problem is the temp sender on the front of the car not reading the temp correctly, making me and the ECU think the car was overheating when it wasn't, thus me shutting the system down before it had got to the correct temperature to open the thermostat thus not letting me bleed the system correctly.

 

Next weekend we are going to re-flush the system again, and get all the crap out, refill with antifreeze, also need to change that sender unit on the top water pipe so its reading the correct value so i don't sit there panicking and turning the engine off when its not even up to temp to open the thermostat.

 

And one for stellaz, we had some help with some rubber piping from our little friend, Jenna the ball mastiff.

 

Good news mate, how happy are you now you didn't break it LOL

Good news mate, how happy are you now you didn't break it LOL

 

thing is im still a bit wary at the moment, need to get my confidence back in it, haven't driven it above 50 yet, think ill do that after the next flush next weekend.

 

But yeah, felt good to be able to drive it.

 

Also been moaned at by Santa pod management to ring them up and get the club booked in for some meets at the pod, we will have the best security there as well lol

Sounds like the car is in better nick than you think mate, the computer has shown you the engine isn't boiling itself to death so trust it a bit more. Get the sender sorted and Roberts your fathers brother.

 

And as for a Pod meet, I'm game.

Sounds like the car is in better nick than you think mate, the computer has shown you the engine isn't boiling itself to death so trust it a bit more. Get the sender sorted and Roberts your fathers brother.

 

And as for a Pod meet, I'm game.

 

yeah need to sort out that temp sender, looks like my after market gauge was actually reading correctly, when i thought it was reading too low and had a sticky needle.

 

OOoooh i so wanna drive down that at night lol