Pressure in cooling system

[pugbug]

Hi guys, not been on for ages! Still driving my stage 3 HDI.

I've got a problem and I can't seem to find a diagnosis

There is too much pressure in the cooling system, the top rad hose is rock solid barely able to squeeze it, radiator is cold, spews coolant from the expansion tank and after a few days it's empty. The bleed valve does not chucks out bubbles lots of bubbles. All things point to a failed head gasket causing pressure in the cooling system?

[Ruan]

Yeah, sounds like a failing head gasket or possibly lifted head... What turbocharger are you using and what IQ is your map requesting?

If you cause it to generate lots of torque (foot down at low RPMs) does it make it worse vs driving barely pressing the accelerator...

[pugbug]

Thanks for the reply. it's a 17/20 hybrid with 360 thrust bearing I'm using. I think using a long silicone pipe to the from the wastegate to the boost controller has caused this, I've seen readings of 27 PSI before it stabilises to 20PSI, too many times has caused it to blow. It's confirmed either a head gasket or cracked head. I've got a spare head, I'm getting that skimmed and ported and it's back on the road.

Reckon it can be taken out and dropped back in a day? I've got air tools.

[welshpug]

sounds like stuck thermostat to me.

[pugbug]

Will try it without stat tomorrow, I let it idle at 2500 rpm with the cap open and it spewed coolant out. It not starting up as well, fires up and shuts back off

[Poodle]

Easily possible in a day if you get a mate to help, still possible by yourself if you're good with the spanners.

[pugbug]

Well she's goosed, running it with the rubber seal out and a glove around the cap to stop water from pissing out, I've got a compressor and huge engine crane, I've owned and worked on the 306 for over 10 years now, so I hope I can I get it in and out in a day, got a spare engine too

Just me doing it, the only help I'll get is my pops bring me the coffee and laughing as I struggle :/

[pugbug]

Decided to do a sniff test on it - Clear

Compression test with results below starting with the cylinder closest to the passenger side first

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I don't get it surely a blown head gasket would show up in the following results, even at 170K that looks like a healthy engine!

[Paul_13]

I'm with WP and stuck thermostat

[pugbug]

it's running with no thermostat lol

[welshpug]

in that case its likely the water pump impeller is not turning.

[pugbug]

Thats what I was thinking, but when the top rad hose is disconnected and the engine turns over there is a massive rush of pressure with water leading me to believe water pump is working.

It's a really odd one, I suspect I may have a cracked head.

[pugbug]

Just cross referenced the compression test values against the book, it's well, well within range of a good and healthy engine, so even though I've got another HDI engine ready to drop it just going to progress with trying to get this one fixed.

Next port of call, do another sniff test on fast idle 1.5K-2K rpm for 15 mins see what happens.

[Poodle]

What happened to cause this, how dd it start?

[pugbug]

No idea. I've been pulling trailers with it over a ton at times. A few years ago I had a hole in the top part of my rad, didn't realise it at the time, but when I got back there was steam coming out the bonnet, it didn't overheat or anything. It does have a large intercooler so that helped.

Tbh I wouldn't want to do anything till I get a definitive diagnosis.

[pugbug]

Confirmed blown head gasket, did another sniff test on it, left for 15 mins on fast idle fluid turned green. Great... was thinking of doing a head gasket change, but being an OHV design gotta get the valves out and then skim the valve seats too. Too much effort. Just dropping another engine in.

[HDi--Power]

Its too much effort to remove 8 valves for the sake of creating a good strong engine? Its about 5 mins to remove the valves

[pugbug]

Haven't got the tools to do the stem seals, plus I need new a few lifters, head skim, new valve seals, head bolts, head gasket, the timing belt and fuel pump and a water pump and the clutch £££ No point really continuing with that engine totally uneconomical. Got one out of a 607 for £50 and sold the fuel pump for £50.

Same engine but the ancillaries are different, totally different!

I've totally removed the EGR system and just made a connection to the heater matrix pipes.

The exhaust manifold hole is ~ 30mm and the turbo to exhaust side to exhaust manifold is 36mm, I got the exhuast manifold ported to match that and double gasketed it.

[toseland]

also, no point having the EGT probe there mate, cools down too much through the turbo, bes tto drill it into the top of the manifold!

[pugbug]

Forgot to mention, that cover that goes underneath the car = good idea, the engine and underside was totally cacked!

Where do you guys put the oil cooler? I had it at the front of the engine and knew it wasn't doing a good job there, but can't find a good a place to mount it as the intercooler is pretty thick and then I've got a large fan in place on the front.

I did have a oil temp probe in the sump and that was registering ~ 120 degrees plus at times! Reckon I can get away without one on my stage 3?

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That was the previous owner. Personally I would have made a blanking plate on the exhaust manifold and tapped the probe in there, which Is what I'm considering. I've had readings of 500 degrees even at that point!

[toseland]

Forgot to mention, that cover that goes underneath the car = good idea, the engine and underside was totally cacked!

Where do you guys put the oil cooler? I had it at the front of the engine and knew it wasn't doing a good job there, but can't find a good a place to mount it as the intercooler is pretty thick and then I've got a large fan in place on the front.

I did have a oil temp probe in the sump and that was registering ~ 120 degrees plus at times! Reckon I can get away without one on my stage 3?

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That was the previous owner. Personally I would have made a blanking plate on the exhaust manifold and tapped the probe in there, which Is what I'm considering. I've had readings of 500 degrees even at that point!

you can, with a little care, drill directly into the top of the manifold where the turbo flange bolts (over that hole). it will be perfectly suited to read then.

you need to push the probe almost all the way down however, or be considerate to where the inlet manifold is as the probe will foul if its not at least dead centre of the hole.


i just had a stage 3... oil temp up to about 130-140 is fine,  My EGTs are running to 700deg on a long VERY hard pull, 

the HDi has an oil cooler on it, its oil/water and you bolt the filter onto it,  this is usually enough, 

[Poodle]

120 is fine for an occasional peak, but you don't want to see it go far past that for a sustained period, iirc it's about 130 where it starts to lose shear stability. That said, i've yet to see an HDi that has problems with oil temperature if it's not being given absolute death on track. Can you not mount it above the intercooler?

Toseland, bear in mind your egts will be miles short of what you should expect as you're still running stage 1 fuelling, that'll go up a lot when we get the map sorted.

[pugbug]

I don't want to do this ever again...! Engine all built up fingers crossed should outlive the car. All of the egr crap removed, no air con gubbins and removing the external oil cooler and buying a bigger nissens rad. I just hope this thing runs well, the R70 pump was a an ebay jobbe.

[Poodle]

Looking good! Should be fine, even the ebay refurbed pumps have to come with some sort of warranty, if it's not fit for purpose just send it back.

[pugbug]

Took the head apart on the old engine, head gasket had no visible tears or even pittance! With it showing at 400 - 450 PSI, I think it was boosting waaay to high, cheapo MBC, only reason why it must have blown it. The honing marks are still there on the block.

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It was for £40 on ebay, but the guy did have a few for sale. I hope and pray this thing fires up tomorrow O_o

[pugbug]

FFS spent pretty much the entire day trying to mount the engine up... Didn't get very far, cannot for the life of me get the bottom engine mount to locate to put the bolt through, imposssssssible! Arranged to take it to a garage, how do you guys do this?

[Toms306]

I leave the mount on the car... Engine just drops back into it then...

[Poodle]

And take the front end off, it's 4 bolts and a few plugs, and maybe the 3 lower bumper bolts if you've still got them. Unplug your light looms, not forgetting the beam adjuster plug, fogs and indicators (through that little hole in the inner wing). Then there's a 13mm bolt at the front of the top edge of both wings which fix the slam panel and another 13mm nut each side behind the bumper - those are easiest accessed from underneath. I'd leave the bonnet cable in as it's a sod to feed back through, just pull the whole assembly forwards and lean it to one side. Then you can get the gearbox in mounted on the engine, rather than balancing it on your chest under the car trying to wiggle it into position etc. Means you've got to drain and remove the rad, but looks like you've done that anyway from the pics.

[Paul_13]

You are doing it the very hard way.

Take the bottom engine fork off completely.
Take the front end off as mentioned above and stick the gearbox on before you lift the engine back in.

Drop the engine in with the gearbox down

[pugbug]

Thanks for the input guys! Ok I'd rather get the box bolted up first, it's a pain to do from underneath. So if I take the slam panel off I should be able to get the engine and box in together in one go?