Navara d22 pressure build up In cooling system

[tommyhodgkin]

Hi all new to forum, am having a problem with navara d22 str with zd30 engine. Building pressure in cooling system, replaced thermostat and radiator cap new coolant, bled and bled and bled, still building pressure suspected head gasket but no water in oil or vice versa. Took to radiator place to do a co2 test on water, no co2 in water??? Short of pulling it all apart I'm at a loss as to what the prob is... Please help...

 

[tatty]

Is the pressure only built up on one hose, then? If so, you've got a blockage somewhere. You can get a system flush, but you might also have air bubbles. Ensure you're letting the coolant boil before you put the radiator cap back on.

 

[user 10312]

Not really familiar with that donk. On some engines there is a bleed usually in the highest point of the coolant system. Sound like you have done that tho. Otherwise dunno check of bubbles with the cap off and thermostat full open. Is the engine running in the normal temperature range?

 

[scottybobcat]

Did you have the heater on when bleeding the system.You may have a air lock in there.

 

[tommyhodgkin]

Yeah heater on when bleeding, and from reading other posts there isn't a bleed point on this motor. Radiator joint said to put front right wheel on ramp to make the highest point the radiator cap, then put sheet of cardboard in front of radiator to get engine to heat up. Once above half on gauge switch off and remove cap and leave overnight. Engine operates at normal operating temp. After a 40 minute drive water was just below top of radiator fins. It's got me buggered, there is nowhere else for air pressure to build up other than from combustion chambers. But no co2 in cooling system...

 

[scooba_285]

could it be the pump?

 

[tommyhodgkin]

Aerating water you think? Do you know if there are any water jackets on intake manifold? Seeing as there is no co2 in water I was thinking of the possibility of boost entering water pre-cylinder, if you know what I mean?

 

[Dion]

Is there any foaming?

 

[tommyhodgkin]

No, just pressure buildup.

 

[Old.Tony]

Welcome to the forum.

Is the ZD30's turbo water cooled? While it seems unlikely, that is the only place I can think of where boost pressure has an interface with coolant.

How much pressure are we talking about? Could you describe what is happening - is it your overflow bottle filling, or is coolant streaming out of your radiator cap? The latter might just be a faulty cap - the coolant system is designed to run at some pressure.

 

[tommyhodgkin]

i have replaced, radiator cap, thermostat, flushed radiator, new coolant, bled and bled and bled. after driving for some time it pushes coolant into overflow bottle and overflows that. when you open the radiator cap there is a big pocket of air, big enough for coolant level to be below the top of radiator fins. no i had a quick look at turbo because i was thinking the same thing, but the turbo only has oil feed and oil return line. i was just curious if anyone knew if there was water jackets in the intake manifold on this particular engine as that is the only other place i could think of where "fresh" compressed air could possibly come into contact with coolant... ie, if there was a leak at intake manifold... i dunno perhaps the co2 tester at radiator place was dodgy and its a head gasket or cracked head, but i doubt that there testing equipment would be r/s.

 

[Old.Tony]

The air has to be getting in somewhere. I'm not sure how the water pump works on the ZD30 but if there's a small pinch in the hose where it's clamped on the suction side of the pump (base of the radiator etc) then it's possible the water pump is sucking in the air through that.

Weird problem you have. Has there been any sign of oily contaminant in the coolant?

 

[tommyhodgkin]

No no oily residue present, I'm thinking the co2 tester didn't pick it up coz it was new coolant, thinking its gonna be head gasket, just gotta find time to clean shed and pull it apart lol

 

[tatty]

Head gasket? Are you sure? It really sounds like a bubble in your system somewhere. You just need to keep trying to catch it out.

 

[tommyhodgkin]

An air bubble wouldn't slowly increase in size though, I've got it apart and think it was the head gasket, I'll repost once it's all back together!

 

[tommyhodgkin]

hi all, just FYI, Got head checked out, vacuum tested and decked. could not find a fault other than when machining face of head, no1 cylinder didnt clean up as well as 2,3 and4. wasn't bad enough to say one way or the other if that was the culprit though. reassembled with new head gasket and head bolts ect. also replaced water pump while everything was apart. only got it going yesterday, done 250kms and no problem so far. fingers crossed.

also installed pyro gauge because it was easy to remove dump pipe while turbo was out ect. boost gauge and manual boost controller and dawes valve on the way also!

 

[ljacko78]

hope the prob's solve tommy.

thanks for the write up as well and sharing the info.

 

[Scott M]

Hi Tommy, I recently purchased a 2003 D22. I am having the same problem, no water in oil/ vice versa, thinking it may be the thermostat. Where is the thermostat located? I took the hose off the top of the radiator and unbolted the casing from the motor but there was nothing in there?

 

[Scott M]

In my case, the temperature gauge is reading normal temp, the coolant is being forced up into the reservoir and is then overflowing. The top hose coming off the radiator is alot hotter then the bottom hose. I'm thinking that I may have a blockage somewhere or its the thermostat. Any ideas would be appreciated! Cheers.

 

[danimac85]

Hey all, I recently had similar problems. Was getting air in the system and loosing water. Still ran like a dream though. So I got it pressure tested and was loosing pressure. Head off, I had a cracked head, rusted glow plug that had hit a piston and cracked that as well...! So after all that I got a low km engine put in. $8000 later and it's back on the road. I hope this isn't your problem mate!!

Cheers..