LUVTruck.com

Hi everyone....I'm new to the board and this is my first post. I just got a 1981 LUV. I didn't spend much on it, and the body is in great shape, with no rust. It has one problem...the truck is leaking oil between the head and the block. The truck seems to run fine, but I've seen some coolant under the truck so I figure it's probably a blown head gasket or cracked head. I don't know how long it's been that way, so I'm a little concerned about other damage. I'm considering four options:

1. Try to repair the head/gasket myself.
2. Have a local shop repair the head/gasket.
3. I found a replacement engine that seems in decent shape, for a decent price. It's from a 78 LUV. Replace the entire engine myself. I don't have a lift so I don't know if that's possible.
4. Buy the replacement engine and have a local shop replace it.

I've got the Haynes manual and the original shop manual. I've done some work on cars over the years, but I'm still very much an amateur. I like learning and doing the work, but this may be over my head. Is it a tough job to repair the head/gasket or replace the engine on a LUV? Anyone have any suggestions? Any ideas how much it would cost if a local shop does the work to repair the head/gasket or replace the engine?

Any thoughts appreciated.

Thanks,

PJ

PJ,

Welcome to the forum.

I'm going to assume you have the 1.8L gasoline engine, since you mentioned that you found a replacement from a '78 LUV and diesels were not offered in those.

At this point, you don't really know if the leak is from the head, the block, or what. So it seems premature to commit to a repair until you know.

On the other hand, if you're considering a replacement engine, you have some options other than the 1.8L. You may want to look at the 2.3, the 2.6, or even a diesel. The 2.3 and 2.6 engines can still be found with low mileage, since they were offered as late as 1995. Not having a lift is just a minor obstacle. I found a used cherry-picker on my local Craigslist for $75. And Harbor Freight has a nice one on sale now for $139, I think.

Jack

_________________
'83 Isuzu P'up Diesel LS - Original Owner
JoeIsuzu@IsuzuPup.com
IsuzuPup.com

Thanks Jack. Yes, it is the 1.8L Isuzu gasoline engine. I did discover that a lift could be found on craigslist at a reasonable price.

How much of an ordeal is it to pin down the source of the leak? It seems I would have to remove the head. How tough is that to do on the LUV? I'd hate to spend hours doing that only to find out I'd have been better off replacing the engine.

Thanks again,

PJ

Since it burns gasoline, I've told you all I know. I hope somebody else will "tag in" for me here.

Jack

_________________
'83 Isuzu P'up Diesel LS - Original Owner
JoeIsuzu@IsuzuPup.com
IsuzuPup.com

You said there is oil leaking between the head & block. What about the source of the coolant leak? Try to isolate it.
The coolant could be leaking from somewhere else, it would be unusual for the head gasket to leak both oil & coolant without the two mixing in either the radiator or the oil pan.
Replacing a head gasket in a G-series engine is about as simple as it gets & very inexpensive, the only special tool needed is a 10mm hex drive for the head bolts. I would do this before committing to an engine swap, especially since you have the shop manual as a guide & anything you are not clear about can be addressed on the forum. If you have helper to assist in lifting the head & intake together on & off it's even easier. Figure half a day for two people, a bit longer for only one. If it turns out the head is cracked & unusable you are well into the process of installing a new head or swapping the engine.
Replacing the engine is not all that hard either, but there are just a lot more things that have to be removed & replaced than with just a head gasket R&R, so it will probably take two people all day, that's if you have all the proper tools and an engine hoist, jack & jackstands & the like.
Call around for shop labor estimates for both, my guess is either will be so expensive you'll want to tackle them yourself.

_________________
'78 Chevy LUV,1.9,4sp,headers,31's,SAS Dana 30,Dana 20,SOA rear w/Aussie Locker, rough body, bought new 12/4/78.
'87 Trooper,2.3,5sp,headers,31's,ball joint flip & spacer,Aussie Locker rear,Superwinch hubs,brush guard w/5.5K winch,more to come.

Yeah I'd be pinning these leaks down a little better before you commit to pulling the head or swapping motors.

Have you seriously cleaned the motor down and then tried to track this oil leak? I just take mine to the do it yourself car wash and hose it down with the high pressure hot soap setting. You want to be careful not to send water into the carb through the air cleaner, and it is really easy to get water up under the distributor cap. I always just packed an extra of those along, but a good bunch of dry rags and maybe some canned air can usually get it sorted. It also can be nice to run it up on ramps and get at things from below too.

Where exactly do you see this leak? Is it all over the front of the head, back, on one of the sides? Oil leaks can travel a long ways and leaking from between the head and the block isn't exactly common. More common is the valve cover gasket and the the two rubber "half moon" plugs at each end. The plugs become hard and brittle, shrinking up, and the gasket does the same. After you do a complete cleaning you should be able to see the leak start to recover the areas you see it in now but starting closer to where the actual leak is.

With oil and all the air movement under the hood, you can't always rely on gravity or what looks like it makes sense. Oil can leak low and then get blown up to a place where it is more visibly collecting, or it can run sideways for a long ways and collect in other areas.

Before you even think of pulling the head loose you should do a compression test. That will tell you a great deal about the condition of the head and the head gasket. If the compression is good I'd exhaust every other possible source for these leaks before cracking open the head.


On the water leak: The first obvious place for that would be the water pump, but it is tough to see where they tend to leak. Usually there is a hole in the body of the pump a little ways back from where the shaft enters the pump. If the seals go, it should leak out there before coming out clear out at the shaft. It is hard to see that hole with the pulleys on, but if it is leaking from behind the pulleys and fan that is the most likely source. New/Rebuilt pump is the cure. Another leak spot is the drain plug for the radiator. If it isn't tight or in good shape it can leak. Then you start looking at the freeze plugs in the block, around the intake, and of course all of those hoses. The radiator hoses are easy to see, but the heater hoses can be tough to see where they go under the intake. Lastly, I've had one truck that had an otherwise good seal on the headgasket that leaked out between the block and head behind the exhaust manifold. It was cured for a time by retorquing the head bolts, but that truck had just had its head re-done. I wouldn't re-torque a head that has been together for a good long time unless you are already committed to tearing it apart.


Hope this helps and good luck!

_________________
95 Isuzu Trooper Daily Driver
86 Isuzu Trooper reliable backup
77 LUV 2wd stock beltway blaster (resting)
79 4x4 LUV project: 2.6L, 5spd, 31s (eventually)

MEPR: Man, my 4x4 makes all other LUVs look good

It won't hurt a thing to check the head bolt torque anytime you have the opportunity, don't loosen them, only check to see if they need tightening to arrive at the proper torque. And you always check the head bolt torque a few hundred miles after having the head off.
Also remember to check the torque on the rocker arm shafts before setting the valve clearance.

_________________
'78 Chevy LUV,1.9,4sp,headers,31's,SAS Dana 30,Dana 20,SOA rear w/Aussie Locker, rough body, bought new 12/4/78.
'87 Trooper,2.3,5sp,headers,31's,ball joint flip & spacer,Aussie Locker rear,Superwinch hubs,brush guard w/5.5K winch,more to come.

Wow...this board is awesome! Very helpful information....thank you.

I put the tracer dye in the oil last weekend and it seems pretty clear the leak is between the block and head, on the passenger side just under the intake manifold. I called a couple of garages and they quoted $1000 to $1500 to do the work, assuming a blown head gasket or cracked head. So, tonight I just started pulling the head myself. Perhaps I should have done the compression test first.

Right now I've got the valve cover off and everything disconnected, this weekend I'll finish pulling the head out and see how it looks. So far it doesn't seem that bad.

I'll update my progress and I'm sure I'll have questions...thanks again for all the great feedback.

PJ

Update....I've got everything disconnected according to the manual. I followed the advice in the manual to pull the head with the intake and exhaust manifold as an assembly. I had to go through the ordeal of a stripped head bolt, but I finally got it out.

Now I'm trying to pull off the head (along with the intake and exhaust manifold). It isn't budging. Are these supposed to be hard to get off? Any suggestions? Is there a tricky bolt somewhere I might be missing? I don't want to start beating on it yet without someone telling me it's supposed to be hard to get off.

Any suggestions?

Thanks,

PJ

Check that....just needed to lift at a different angle. I've got it off. Now for the inspection.....

Update - I got the head off and inspected everything. It appears to me that the problem was a small, removable piece of the head gasket, which surrounded one of the head bolts. This piece had become partially loose, so that there was a gap between it and the rest of the gasket. This is precisely where the leak occurred, so it seems logical that this was the source of the leak. I did not see any cracks in the block or head, or any other problems with the gasket. Other than that, everything seemed to be in good shape. This seems like kind of a flimsy gasket design, creating a potential weak spot.

Am I right to think this was the source of the leak? Should I just replace the gasket and see if that solves the problem, or should I do other things as well while I have it apart? Should I have a mechanic inspect the head? I put a straight edge on it and it seemed even and level.

Any trick to replacing the head gasket? There's a little residue left on the block after removing the gasket, does that need to be perfectly clean? Any cleaning tips?

It appears as if oil and coolant were mixed....should I do something to address that while I've got it apart? Does the system need to be flushed?

I've attached pictures.....my finger is pointing to the loose spot on the gasket. I've also attached a picture of the block.

Sorry for so many questions....this is my first time! Any feedback is appreciated.

Thanks.

Yes that is where the leak would be. That is an oil passage where the oil comes up and goes to the head to lubricate the cam bearings, and valve assembly. Of course clean the head and block surfaces thuroughly removing all traces of old gasket material, etc.
Yes it looks to be a simple gasket failure in that area. I always used FelPro brand gaskets, as they seemed to be of the best quality at that time at least, 80-90's. They had a band of blue rtv sealer around all the water port areas.
Also another hint: place a dab of sealer under the head gasket in the tiny crack where the block joins the front timing chain cover, just a tiny dab with your finger. Will stop a sometimes very small oily leak in that area.

Thank you! Am I okay just replacing the head gasket or should I replace the exhaust and intake gaskets while I'm at it? Could that be done later without pulling the head?

What's the best thing to use to clean the surfaces?

Scrape the block and head surface with something like a single edge razor blade- you can't get them too clean- then wipe with a rag soaked in brake cleaner or the like. Stuff the bores with rags to keep scrapings out, blow out with compressed air if possible. Don't leave oil or water in the head bolt holes in the block, blow out with compressed air if you have it. Put the head gasket on dry, no sealant except for the slight smear (read thin) at the block to timing cover juncture as described.
You probably need to change oil before starting since the coolant residue in the head made it's way to the bores (and probably past the rings into the crankcase). You did drain the radiator before starting the head removal, right? So new coolant as well, 1 gallon into an empty system, then fill with water makes it just a bit over 50/50. Soak up all the coolant you can with paper towels or rags or use compressed air, you don't want any getting on the sealing surface.
If the intake & exhaust gaskets are not leaking leave them alone.
I don't see where you have sourced the coolant leak, check the heater hose that connects to bottom of the intake before you re-install a soft or split hose- go through the fender well to re-connect this, you can maybe see it instead of doing it by feel. Same if you ever have to R&R the intake gasket or a starter.
The two little hex bolts that go through the front of the head into the timing cover are not head bolts & only torque to about 14 ft-lbs (or just good and snug). If you drop one into the timing cover you have to lower the oil pan to retrieve them, so put the rag back around the chain before trying to install the bolts.

_________________
'78 Chevy LUV,1.9,4sp,headers,31's,SAS Dana 30,Dana 20,SOA rear w/Aussie Locker, rough body, bought new 12/4/78.
'87 Trooper,2.3,5sp,headers,31's,ball joint flip & spacer,Aussie Locker rear,Superwinch hubs,brush guard w/5.5K winch,more to come.

Thanks.....great tips. Re sourcing the coolant leak.....the gasket alone cannot be the cause? I didn't see any other possible leaks when I took it apart.

One more question - as you can see in the picture of the block, there is still one head bolt in there. It was stuck, and it stripped when I tried to remove it. I drilled out the bolt head to get the head off. Now that I've got a lot more room to work to try to get it out, I've used penetrating oil and locking pliers to try thread the bolt out, to no avail. Should I just persist with the penetrating oil and pliers, or does anyone have any other suggestions?

Thanks!

I would continue to use the locking pliers (vice grip) and soak it with penetrating spray (Gumout) about every time you walk by it. Best stuff I have ever used is Gumout Carburator cleaner spray. It seams to just eat corrosion and will come out after you work it back and forth with the vice grip pliers. A small pipe wrench may also get it if the pliers doesn't get it.

Look the gasket over very carefully at the coolant passages, if it was a head gasket leaking coolant there will be evidence of coolant travelling from one of the passages to the exterior of the head, the area that is damaged is an oil passageway (hence the oil leak) but you said the coolant wasn't leaking into the oil but onto the ground. A coolant leak to the outside generally will leave leak stains, look for them where they would run down the head or block, look the intake manifold, water pump & radiator over very carefully & all the rubber coolant and heater hoses. As I said before it would be highly unlikely for the head gasket to leak both oil & coolant at the same time without the two mixing, but if it happened there should be obvious evidence of separate leaks at an oil passage and a coolant passage.
The broken head bolt must come out, whatever works. You may have to get someone to weld a nut to the stub end, cover the rest of the engine first, welding slag in the engine is not good. I'm surprised it isn't easy to unthread with the head removed, all the pressure holding it tight is the bolt head against the cylinder head- unless someone put thread locker on it. Head bolts need to me lightly oiled, no sealant, & the holes clean. You're going to need at least one head bolt, check the others, if the socket head is not crisp or you are concerned it may round in the future replace also.

_________________
'78 Chevy LUV,1.9,4sp,headers,31's,SAS Dana 30,Dana 20,SOA rear w/Aussie Locker, rough body, bought new 12/4/78.
'87 Trooper,2.3,5sp,headers,31's,ball joint flip & spacer,Aussie Locker rear,Superwinch hubs,brush guard w/5.5K winch,more to come.

Thanks for all the tips. I may have misspoken.....I think the coolant and oil definitely were mixed. I put the tracer dye into the oil and it made its way into the coolant.

I have had to do the same with that same head bolt more than one. It is sandwiched between the #2 and #3 exhaust ports and heat near welds it in place making it very hard to get out with the head on. Once the pressure from the head is off though, it came out with relative ease. I used a large pipe wrench on the last one I did, just take care not to drop the wrench onto the top of the block and scratch or dent it. The other time I've done this the bolt came out quite easy with vice grips.

Also give that bolt several good smacks from the side with a hammer. That will help break loose its grip on the block.

Failing that, welding a nut over the top can work, or grinding two sides flat and using a big crescent wrench on it can work too.

_________________
95 Isuzu Trooper Daily Driver
86 Isuzu Trooper reliable backup
77 LUV 2wd stock beltway blaster (resting)
79 4x4 LUV project: 2.6L, 5spd, 31s (eventually)

MEPR: Man, my 4x4 makes all other LUVs look good