Blown head gasket

4260 Views 63 Replies 13 Participants Last post by cmf5, 3 mo ago

cmf5

Discussion Starter · 9 mo ago

I think the Trooper’s head gasket gave way. Pretty sure it didn’t overheat, though. Heard what sounded like an exhaust leak at freeway speeds and a distinct loss of power, pulled over and she idled super rough (almost died). Oil is lighter than when I last checked it but coolant isn’t foggy. Pretty sure I see wetness on either side of Cyl #4 (closest to firewall). Knew I’d have to do this at some point, but always annoying when you’re left stranded.

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cmf5

Discussion Starter · #2 · 9 mo ago

First step will be a compression test when I have time.

Any gasket kits people recommend? I’ve seen advice to get a genuine Isuzu gasket but I can’t find it for sale anywhere. Any options are appreciated, don’t want to do this again.

Any preventative maintenance or replacements I should do while the head’s off?

Thanks

Tentin

· #3 · 9 mo ago

I think Felpro is the only aftermarket brand on here that people have had luck with. Lots of problems with the cheaper brands.

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Ed Mc.

· #4 · 9 mo ago

You can get an OE Isuzu head gasket from our resident Isuzu Guru Jerry Lemond in Dacula, GA. JLEMOD on this forum, you can message him. Or contact him at [email protected]

Use Large Font in deference to Old Eyes.

Drain your oil, if it is contaminated with coolant you don't want that mixture in there for long, coolant eats bearings.

Besides a compression check, do a pressure test on the cooling system, that may tell you something.

If you have to pull the head, easier to remove the hood then pull the head and intake out as a unit. You can undo the EGR pipe and unbolt the exhaust manifold; tie it to the side, out of the way.

If you want to remove the intake before pulling the head, about the only way to do that is to remove the upper plenum. Then you'll have access to the mounting hardware.

If the head is original and, especially if the casting # at the firewall end is low (i.e. #1 or #2), recommend getting a new head. By the time you have the head pressure-checked, surfaced (as required) and a valve job, you'll have a ton of $$$ into machine shop labor and material. New head is somewhere around $650 from Clearwater Cylinder Heads in Florida, a much better, more reliable option. New design and better materials drastically reduce the possibility of cracking and exhaust valve burning, which was a big problem with the earlier run of factory heads.

Very important to have a good head gasket in there and I wouldn't use anything but OE, as long as they're available. Fel-Pro would be the 2nd choice.

Anyway, check everything over carefully, maybe it's not a blown gasket. G'luck with the repairs.......ed

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MrDunge

· #5 · 9 mo ago

Ed Mc. said:
You can get an OE Isuzu head gasket from our resident Isuzu Guru Jerry Lemond in Dacula, GA. JLEMOD on this forum, you can message him. Or contact him at [email protected]

Use Large Font in deference to Old Eyes.

Drain your oil, if it is contaminated with coolant you don't want that mixture in there for long, coolant eats bearings.

Besides a compression check, do a pressure test on the cooling system, that may tell you something.

If you have to pull the head, easier to remove the hood then pull the head and intake out as a unit. You can undo the EGR pipe and unbolt the exhaust manifold; tie it to the side, out of the way.

If you want to remove the intake before pulling the head, about the only way to do that is to remove the upper plenum. Then you'll have access to the mounting hardware.

If the head is original and, especially if the casting # at the firewall end is low (i.e. #1 or #2), recommend getting a new head. By the time you have the head pressure-checked, surfaced (as required) and a valve job, you'll have a ton of $$$ into machine shop labor and material. New head is somewhere around $650 from Clearwater Cylinder Heads in Florida, a much better, more reliable option. New design and better materials drastically reduce the possibility of cracking and exhaust valve burning, which was a big problem with the earlier run of factory heads.

Very important to have a good head gasket in there and I wouldn't use anything but OE, as long as they're available. Fel-Pro would be the 2nd choice.

Anyway, check everything over carefully, maybe it's not a blown gasket. G'luck with the repairs.......ed

I have done half a dozen head gaskets on those engines to include my own twice. Why twice you say? Bc I didnt listen the advice that ED and several other gave back in the day and didnt use a OEM head gasket. Have learned my lesson. Get in touch w Jerry if you need one, and take Eds advice on disassembly. If you have questions you can PM me personally and Ill give you my number and we can chat.

Reactions: 1

turnerd

· #6 · 9 mo ago

MrDunge said:
I have done half a dozen head gaskets on those engines to include my own twice. Why twice you say? Bc I didnt listen the advice that ED and several other gave back in the day and didnt use a OEM head gasket. Have learned my lesson. Get in touch w Jerry if you need one, and take Eds advice on disassembly. If you have questions you can PM me personally and Ill give you my number and we can chat.

Ditto. Also did my 2.6 head gasket twice since I cheaped out and didn't use OEM the first time.

itsmehb

· #7 · 9 mo ago

Also did several using both fel-pro and an oem from Jerry. All turned out well, but if I do any in the future it will be an oem .You can see the quality of the oem when looking at it compared to others.

lowzone

· #8 · 9 mo ago

one mistake is using gasket tack. the gasket has to be able to float between the cast block and aluminum head. made that mistake ONCE....Fel Pro is good, OEM is best.

cmf5

Discussion Starter · #9 · 9 mo ago

Ed Mc. said:
You can get an OE Isuzu head gasket from our resident Isuzu Guru Jerry Lemond in Dacula, GA. JLEMOD on this forum, you can message him. Or contact him at [email protected]

I emailed Jerry. I'll try to get an OE gasket, otherwise I'll stick with Felpro.

Ed Mc. said:
By the time you have the head pressure-checked, surfaced (as required) and a valve job, you'll have a ton of $$$ into machine shop labor and material. New head is somewhere around $650 from Clearwater Cylinder Heads in Florida, a much better, more reliable option.

I was just quoted $350 for a cyl head refinish and valve job. I see Clearwater charges $455 for a new head minus the cam. Any issues using the old cam, or buying a Delta or Jerry cam for use with a Clearwater head?

Thanks

turnerd

· #10 · 9 mo ago

cmf5 said:
I emailed Jerry. I'll try to get an OE gasket, otherwise I'll stick with Felpro.

I was just quoted $350 for a cyl head refinish and valve job. I see Clearwater charges $455 for a new head minus the cam. Any issues using the old cam, or buying a Delta or Jerry cam for use with a Clearwater head?

Thanks

I've been running a Jerry cam in my Clearwater head for a while with no issues at all. Note that the clearwater head has two differences from stock: 1- better coolant flow 2- no smog ports (an issue if you have emissions testing).

cmf5

Discussion Starter · #11 · 9 mo ago

Ah. Guess a Clearwater head isn’t in my future then. I’m in CA.

Ed Mc.

· #12 · 9 mo ago

Can't they drill the EGR ports in the head? There might be an extra charge for that, but it would be worth it.

BTW did that cyl head refurbish estimate include a pressure check and examination for cracks? DO NOT reuse an Isuzu 4-cyl head unless it's pressure-checked. Unless you want to take the risk of dumping all the labor, time, and parts into a used head that may already be cracked or have issues sometime down the road. Been there. Done that. Don't recommend it.

turnerd

· #13 · 9 mo ago

Ed Mc. said:
Can't they drill the EGR ports in the head? There might be an extra charge for that, but it would be worth it.

BTW did that cyl head refurbish estimate include a pressure check and examination for cracks? DO NOT reuse an Isuzu 4-cyl head unless it's pressure-checked. Unless you want to take the risk of dumping all the labor, time, and parts into a used head that may already be cracked or have issues sometime down the road. Been there. Done that. Don't recommend it.

I'm not sure on drilling the ports but one could certainly ask. Ditto on the pressure check.

cmf5

Discussion Starter · #14 · 9 mo ago

Good thoughts. Thanks. I’ll reach out to Clearwater. If that’s beyond their scope I’ll double check with the machine shop.

itsmehb

· #15 · 9 mo ago (Edited)

My first 2.3 clearwater head I bought was complete with cam. My second for my 89 2.6 was without the cam, The head comes with the cam caps. Just need to swap over the cam and rockers. Had no issues with mine, and it's running great.

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cmf5

Discussion Starter · #16 · 9 mo ago

itsmehb said:
My second for my 89 2.6 was without the cam, The head comes with the cam caps. Just need to swap over the cam and rockers. Had no issues with mine, and it's running great.

Any issues with loose cam bearing fits or any other concerns moving an old cam into a new head? Sounds like Jerry's all out of cams at the moment.

itsmehb

· #17 · 9 mo ago (Edited)

I didn't have any, and don't really remember reading of any problems others have had ordering the head without the cam. I should have mentioned the rocker shafts and metal rocker retainers must also be swapped over to the new head.
along with the cam and rockers.

DSUZU

· #18 · 9 mo ago

All good advice. Missing is: Make sure that block surface is PERFECTLY clean. Then check it with a straightedge front to back and across. After head installation, be sure you do the re-torque of the head bolts at 1,000 miles. Dennis

1991 LS Trooper 2.8 V6 5 speed conversion (Sold)
1989 LS Spacecab 2.6 5 speed 4x4 manual hubs, Rodeo torsion bars, extended shackles, 2" lift, K&N air filter (drop in), dump bed conversion, burgundy interior change, warn brush bar. Engine is bored .020 oversize and upgraded to 1994 pistons, head and EFI system.
Previously owned: 1987 Trooper II LS, 1989 Trooper (parts only), 1994 Trooper 3.2 Auto, 1997 Rodeo 2.6 5 speed, 1993 shortbed pickup 2.3 (project - sold) 1992 Rodeo 4x4 LS (parts car, devoured by Spacecab needs) plus some 70 plus other non Isuzu vehicles over the years. 1994 Amigo devoured to provide head and EFI system.
Heavily damaged by engine compartment fire while driving on March 24th 2018, condemned by insurance company and taken on March 30th 2018

.

http://forum.planetisuzoo.com/viewtopic.php?f=15&t=64060
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Ed Mc.

· #19 · 9 mo ago

Chase out the head bolt holes in the block with a 12mm x 1.50 bottoming tap then blow out with air, carb cleaner, etc. A razor-blade-type paint scraper makes a good scraper for the block surface.

There shouldn't be any issues with using the existing camshaft, long as the cam lobes and journals look good.

Delta Camshaft in Tacoma, WA offers a "272" grind which isn't too far off from the Jerry Cam. They can grind your cam if they don't have any in stock. Otherwise they'll ship one to you and you send back your good core cam.

www.deltacam.com

DeltaCam.com

We manufacture horsepower!

www.deltacam.com

www.deltacam.com

Here's an old thread with my old RS, the new owner had some good comments on using the Delta cam:

www.planetisuzoo.com

New Head and Delta 272 Cam Install

Hello all, spring is here, and it's time for me to dig a bit deeper into the RS I picked up of from Ed Mc last year. I've been whittling down a list of smallish projects this winter, and am preparing to install a new head with a Delta 272 cam. The original engine had a badly burned valve and a...

www.planetisuzoo.com

www.planetisuzoo.com

Scroll down a ways for the comment from "Oregon RS".

Check the rocker shafts and rocker arms for wear. I had some severe wear on my old Spacecab 2.6 when I had a valve job done. Jerry Lemond saved me a lot of $$$ with a good used set of rocker arms & shafts. Pull the rocker shaft away from where it sits on the shaft and check the rocker shaft for scoring.

Check each rocker on an unworn area of the rocker shaft, for slop. Anything more than the slightest side-to-side free play is unacceptable and will likely lower your oil pressure. Replace as needed. Rockauto carries rocker arms but they ain't cheap! They also have the intake rocker shaft in stock, but you'll have to search around for the exhaust shaft if you should need a replacement.

HTH............ed

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Ed Mc.

· #20 · 9 mo ago

Oh, I forgot to mention that if you use a performance cam in these heads, to correct the valve geometry you will likely need to install a set of lash caps. The lash cap fits on top of the valve stem and the extra thickness keeps the valve adjuster screw from contacting the valve stem at an excessive angle.

Fortunately the 8mm lash caps used in VW air-cooled applications are a perfect fit.

They're inexpensive and readily available:

empi 4006 lash caps for sale | eBay

Get the best deals for empi 4006 lash caps at eBay.com. We have a great online selection at the lowest prices with Fast & Free shipping on many items!

www.ebay.com

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