Shop Isuzu Head Gaskets

how big a job is repacing the head gasket on an isuzu trooper. 1990 modle

Hey Randy
Autozone has some pretty good repair info for your Isuzu on there website, click the link for the cylinder head replacement:
http://www.autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/18/3b/c0/0900823d80183bc0.jsp

1988 Izuzu Impulse
2.0 4ZCI Turbo Intercooler
104,000 miles

Runs and drives great, smooth running and smooth idleing. It blows white smoke from exhaust pipe once it warms up. The smoke has a coolant smell, not an oil burning smell. The warmer the motor gets the more smoke coming out, but does not overheat. Oil looks good, not milky. Neighbor told me that turbo might be bad but I don't know.

Also must add that the car does not overheat and the oil appears normal, no water in the oil. So the head gasket could allow coolant to seep and then stop seepage once it warms up?

I found a compression leak tester, and will try that this afternoon. That should confirm or eliminate the possibility of a bad head gasket or cracked head. Right?

Diagnosing a head gasket is inconclusive till you are actually there. What you need/want is to be sure that you have to go there to find the real flaw - gasket or perhaps the head/manifild or block has the flaw.

This one seems like it's just started or may have even been a false alarm so far but you have the warning to keep an sharp eye on it. You may test when it's not having an issue and test will be inconclusive. When parts are off you can usually see where the trouble was and by then you are going to replace gasket anyway but still should send out head for machine shop inspection or risk a quick re-do of the job.

If you do find compression equally low in adjacent cylinders that does suggest problems between the two. The check list goes on. Coolant in oil, oil in coolant, exhaust gasses in cooling system, -- plain leaks to the outside possible. Spark plugs tell a tale too as to whether they are or have been exposed to burning coolant, oil and other problems. Always nice when they all look about the same.

The up front testing can prevent wasting all the work to find some other problem later that fooled you. Speaking for myself - I hate to make the call on head gaskets as they are lots of work and $$ and being wrong would really stink.

THIS COULD ADVANCE TO REAL BAD IN NO TIME so be ready for that. Anything that won't stay broken for testing is a mechanic's nightmare,

T

I let the car warm up to operating temperature today and when I turned it off I heard a faint hissing/gurgling sound on the driver side of the motor under the exhaust manifold. I couldn't see under the manifold but the side of the engine looked wet and coolant was dripping under the car. Considering pulling the head to see if it's the head gasket, even though the oil looks fine.

I've been pounding my head against the bumper on this one for about two months now. Here is what I'm working on:

1999
Isuzu
Rodeo
2.2L inline 4
87k miles

I discovered about three weeks after I bought this rodeo that there was a slight leak in the head gasket. Water was leaking into the number 4 cylinder. Water was not getting into the oil, and the car was not burning oil, so I just put some stop leak in the radiator to limp it along until the weather warmed enough to replace the head gasket. This worked for about a month, but the loss of water got to bad to put the head gasket replacement off any more. The car never overheated in a melt down type of situation. Anytime it started running a little hot, we would pull over and put water in it. Since the car was just for my wife to run around town(5-10 miles a day tops), just topping off the radiator before setting out was sufficient.

When the head gasket was removed, it was obvious where the water was leaking; the head gasket was de-laminated and eroded between the main water journal and the number 4 cylinder. None of the cylinder walls looked scalded, the head measured to be dead flat and none of the valve seats looked unusually worn nor burnt, so I just cleaned everything up and reassembled the engine.

The test start was rough to say the least. It took about 5 minutes of cycling the key and cranking the motor to finally get it to start. It ran very very rough. I let it idle for a few minutes, and took it for a drive up the road and back(about a block) to see if it cleared up at slightly higher RPMs. Well, it did a little, but I noticed a serious vacuum leak. The nipple for the vacuum on the EGR broke loose. Simple fix to just remove the broken nipple from the hose and press the hose back onto the remaining nipple piece. This cleared most of the rough running, but not all of it.

With the engine running more smoothly, I decide it should be safe enough to take it to autozone to have them pull the diagnostic codes. Only two codes come up. One is a sending unit error(very common with the rodeo) and the other is a dead miss on number 3 cylinder. I confirmed this by pulling the plug boots off the plugs one by one, and pulling number 3 boot had no effect on the engine at all.

I put a compression tester on it, and every cylinder tested right around 150-155 PSI. The spark on number three was a little...weird for lack of a better term. It was sparking, but rather than being a thick blue spark in the 1/2 inch range like the other cylinders, it was a long thin white spark up to 2 inches in length. I replaced the ignition coil pack, and now it sparks just like the rest.

Having eliminated spark and compression, moved on to fuel. After letting the engine run for a few seconds, I pulled the spark plug from number 3, and it is soaked in gas. Not being satisfied with this as proving sufficient fuel, i swapped the injectors between cylinders 1 and 3. Still no change.

Using a screwdriver, I listened to the lifters through the valve cover. Number 3 was more noisy than the other 3, so I pulled off the valve cover and listened closer with a piece of hose. The noise is the same between all 4 lifters on number 3 cylinder, but different than the other 3 cylinders.

I'm stumped. Anyone have any ideas? The ignition timing is non-adjustable. This motor was built to be more of less idiot proof, but also dang near impossible to diagnose.

UPDATE:

Just ran it back to autozone to pull the codes again. It came back with "multi cylinder misfire" as well as error code P1627, which I've been told is a malfunctioning sending unit in the fuel tank. Dang thing died on a 4 lane highway on the way back.

Hi All,

First post here. Have this nagging issue with our import, a 1991 Isuzu Stylus S with 1.6 SOHC 4-cylinder.

Originally I thought I was simply replacing a leaking head gasket due to coolant and oil leaks around #4 cylinder.

Removed the head and sent it to the shop for cleaning, checking and milling (shop replaced valve seals and cam seal from HG kit). Put it all back together and it burned 2 quarts of oil in 300 miles. Pulled it apart and removed and replaced the rings, honed the cylinders and re-installed the pistons.

After replacing the head a second time it was still burning oil, and now there was a lot of heat coming from the cooling system.

Removed the valve seals installed by the shop with new ones. Stopped burning oil. Noticed that pressurizing #4 while replacing the seals also pressurized the cooling system enough to force coolant out through the cap and hoses. Cylinders 3, 2 and 1 no problem.

Cars runs OK, 200 lb compression on all 4 cylinders. Oil level is good, but oil is getting black faster than I would expect. Coolant may be entering the engine when running (probably #4?), but no white smoke, no external leaks and no coolant in the oil. If the coolant is 'evaporating' (humor) or being burned it isn't very much, almost imperceptible. NOTE: Car just passed its e-test with flying colors.

I tried Irontite All Season sealant and that helped a little, but the engine is still pressurizing the cooling system. Coolant enters the recovery tank only when cold and the cap is released. BUT, coolant will not re-enter the rad from the recovery tank when cold.

I've built a number of engines (mostly NA 6 and 8 cylinders) and never had this much trouble before sealing an engine or installing head gaskets.

Question:

What am I missing? a) head gasket (AGAIN??) b) cylinder head? or c) block?

Good points.

It was burning oil right after the head was originally replaced, 2 quarts in the first 300 miles. The theory at the machine shop was that now that the top end was sealed, the rings were in need of replacement. Once the rings seated it still puffed oil (and moisture) on start-up (valve seals) at the tailpipe and appeared to be running rich. So I wrestled that one to the ground, finally replacing not only the rings, but later the valve seals, valve seals in a head that my hands had not touched up until that point.

Before I added the coolant sealer it had a 'hint' of anti freeze or moisture coming out the exhaust, but it was so little that it didn't create any white smoke. What was coming out the back was predominantly blue smoke. The blue smoke was present at start up, and during the break-in period (about 1500 miles) while the rings seated. But it never completely stopped, until I replaced the valve seals.

The ECM and emissions are so 'caveman' that it is pre-OBDI and no one has a cable or diagnostic software to read the ECM in real time. Saturn SAAB Isuzu where we bought the car in 1991 used to have these tools, but when the brand disappeared the tools went with it. Actually that isn't completely true, the Lotus Elan group of people have cables and diagnostic software but I got the impression they thought the Isuzu Stylus was not even close to their 'breed' even though the engines (and likely the electrical systems) all come from GM Lotus and Isuzu development. But this is another topic, and I digress.

The coolant issue manifested as excessive heat when the car was running. Ordinarily the cooling fans never come on, particularly when the ambient temperature is below 50 deg F. The fans will come on anytime the AC is activated however. Plus, the cooling system now began pressurizing at start-up. It also had small champagne bubbles. Adding the coolant sealer reduced the excess heat issue, but the cooling system was still pressurizing during run.

I kept watching the recovery tank to see if the fluid went down, but it didn't appear to measurably, and standing behind the vehicle didn't give any indication of an anti freeze smell, or residue. As a bonus however, now that the valve seals have finally been replaced with new ones, it stopped puffing oil. Almost there, I guess.

If you were a betting man, would you equally weigh the head and the block as a root cause, or lean toward one over the other and why?

What else might help isolate it as one over the other (since I can't do the recommended diagnosis for the reasons stated earlier).

I don't want to jump straight to a solution, but it looks like that is where I am.

That was a very long post of pretty much useless information.

You don't have any coolant loss........
You don't have extreme overheating........

Your testing is flawed and I seriously doubt you have any head or head gasket issue but you sure will have a cooling problem if you continue to try to fix a non-existing problem by filling the system with sealer.

I believe that if you pressurize a cylinder with compressed air from your air compressor and you see bubbles forming in the coolant that is a sign you have a sealing issue. Wether it is due to a poorly sealing head gasket, cracks in the head, or cracks in the cylinder bore, the head has to come off and the cause determined.

If you have compression leaking into the coolant system that severely, you will superheat the coolant with combustion gases and overheat in real short order which this car is not doing. You will also fill the cylinder with coolant on shutdown, if not all the time and this car is experiencing none of that so I really doubt the test findings here. I've never seen a head gasket open between combustion and water jacket that didn't overheat or consume coolant.