[BlackSmoker]

Hi guys and gals. I was wondering if HZJ 73, HZ1 engine is prone to head gasket failure? I recently pulled my tent trailer over some steep roads over to Tye on Kootenay lake. I was watching my temp gauge and everything was fine then the temp went a little above half. when I got to the summit and started down hill it was smoking which wasn't normal. Then it seemed to go away and I noticed it was low on power. I checked the coolant no sign of higher pressure and no oil. I checked the oil and no water in it. I ran some Lubromoly though the tank with the next fuel fill up. I am buying a compression leak down tester from Lordco. I was wondering what normal compression is at 154000 km.

Compression pressure:
IPZ and 1HZ
37.0 kg/cm2 (526 psi, 3,628 kPa) or more
1HD-T
35.0 kg/cm2 (498 psi, 3,432 kPa) or more
Minimum pressure:
IPZ and 1HZ
27.0 kg/cm2 (384 psi, 2,648 kPa) or more
1HD-T
25.0 kg/cm2 (356 psi, 2,452 kpa) or more
Difference between each cylinder:
5.0 kg/cm2 (71 psi, 490 kPa) or less




This is out of my manual.Any help would be great. Cheers

[simonliew]

Don't know any 1HZ with head gasket problems,what was the elevation at the summit,yo uwill loose power without turbo at over 6000 feet.
l have seen a few 1HZ came with plastic impeller on the waterpump,if the engine got hot on the 1HZ,the plastic impeller may spin loose on the shaft and cause overheating underload.l have seen two,replacement waterpump usually have steel impeller.
Simon

[Radd Cruisers]

The 1HZ is not prone to head gasket failures. The gaskets are usually MLM (aka MLS) and are very robust gaskets that are not prone to failures.

The smoke and low power may be related to elevation, fuel filtration (plugging filter), air filtration (plugging filter) or something else... like going down a hill for a long time on the compression (diesels don't generally have very good compression braking without the aide of an exhaust brake or an intake butterfly).

If you're oil and coolant are in good shape, and your engine was not over-heating (and the half-way mark is not over-heating if your gauge is working), then you have little to worry about.


~John

[roscoFJ73]

Originally Posted by simonliew

Don't know any 1HZ with head gasket problems,what was the elevation at the summit,yo uwill loose power without turbo at over 6000 feet.
l have seen a few 1HZ came with plastic impeller on the waterpump,if the engine got hot on the 1HZ,the plastic impeller may spin loose on the shaft and cause overheating underload.l have seen two,replacement waterpump usually have steel impeller.
Simon

The plastic impeller is the OEM type and mine lasted 250000 before the gasket give up.The plastic is not like shopping bag plastic
The plastic blades are longer and thinner and I suspect they may be more efficient and pump more coolant then the aftermarket type.
IMO, the OEM is worth the extra $30

The one with metal blades is a Croc brand and is supposed to last ok.

[prado t]

So how was it on the Salmo- Creston? Did the temp guage climb? At roughly around 1500meters your 1HZ will smoke abit and probably lose some power due to lack of turbocharging. If it is fine back in Trail then you have nothing to worry about. I used to waterski from Kuskanook to Tye.

[BlackSmoker]

Actually I did the compression and it is good well balanced only a difference of 15-20 psi very good I think. I did run some Lubromoly through the filter and changed the filter. I re-adjusted the injection pump and it runs alot better. The temperature doesn't really fluctuate alot unless I am pulling my tent trailer. Salmo - Creston is not a problem at all unless it's full throttle. Rossland - Trail hill is very steep if I drive the speed limit the gage doesn't move too much. I don't have a pyro to really tell. I am going to put a Garrett GT2876R turbo on it this spring but finding the long section of the manifold is hard to find. I will probably build a log manifold if I can't find one. Water to air intercooler too. Cheer

[lshobie]

I don't think you have a High altitude compensator on your truck - that is why it was smoking, the temp gauge going up is par for the course from a long steep climb under load, 1HZ's don't have head gasket problems. You should be all right unless you are loosing coolant. When you say fuel pump adjustments do you mean fuel adjustment screw or pump timing? If you mean pump timing be very careful or you ca end up with a real problem.

Adding the turbo is awesome, I put a turbo and water/air intercooler my HZJ79 this summer - works great!