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Discussion Starter · #1 ·
Im starting to think my car hates me. :(

Just got it back from rebuild #3 (see "Today is the Day" thread), and now it's showing all of the symptoms of a blown head gasket...

Unexplained coolant loss, overheating, air in the system, white smoke from the exhaust on startup, smell of exhaust in coolant, etc.

I did a "combustion test" to confirm that there are exhaust gases in the coolant, and sure enough it turned yellow (from blue).

So I'd like to track it down to the particular side of the engine with a compression test.

Anyone know what the easiest way is to disable the V8 ignition so that the starter will crank but the engine will not start?
 

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Pull the two fuel pump fuses to disable the fuel when doing your compression test. Removing fuel rather than spark avoids washing the bores.
 

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Cal H
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Cutting fuel is good but after cutting fuel would the engine not spin easier if all the plugs were pulled? You have to pull them anyways to do a compression check
 

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Oh man!!! I really feel for you...really, really sorry to hear that. Sounds like you have my kind of luck. Sometimes you feel like you are being punished for even trying. :(

Will the shop that did the work warranty their work? One way or the other, be sure to document everything.

Hoping it turns out to be something super simple, but either way, hope you get it all resolved and back on the road real soon.

Roy
 

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Discussion Starter · #5 ·
Thanks, all. Yes - I definitely feel like there must be some karmic punishment or something going on here!

Pulled fuses B3 and B4 to kill the fuel pumps and did the compression test.

Right away I found the culprit - cyl #4 (furthest back on the passenger side) is wet. Assumably it's coolant (it definitely wasn't fuel). Other cylinders were dry.

Im not sure how to interpret the compression test results, but the wet cylinder actually had a higher compression number than the others (160 psi vs.150 on the next cylinder over, and 130/132 on the opposite side). But the engine was cooling down as I went too. The workshop manual shows 155 +/- 15 as norm.

Regardless of the compression numbers though, the wet plug and cylinder is a smoking gun.

The mechanic has offered to take it back, but I'm undecided what I am going to do yet.
 

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Discussion Starter · #9 ·
Pressure test the radiator.
if head gasket, it can be replaced but i hope it's not liner issue
Hopefully not a liner issue - on all of the rebuilds it's gotten the new Hylomar sealant.

From all of the bleeding of air and adding of coolant I can say that the system is definitely holding pressure, but if we dive into fixing this we will have to check everything (again).
 

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If you are certain anti freeze leaking somewhere - you really don't have a choice except to open it slowly and check the edges of the head gasket in relation to the cylinder area.

If the water is leaking through liner, then that's a tough one.
But if its me, I will perform an anti freeze pressure leak test...just to be certain I am in the right diagnosis before opening the engine. If you have bore scoop you can check each cylinder after the pressure test. It's a simple quick test.
 

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Boy, sorry to hear that.. Seems that shop that did this should cover it..
 

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There are other tests you can do to confirm your results. If you pressurize the cooling system you can see if you get coolant into the cylinder and you can do a differential leak-down test to see if you get bubbles into the cooling system. The high pressure could be caused by a leak between two cylinders AND the cooling system. It can also be a lot of carbon from unburnt fuel increasing the compression ratio.
David Teitelbaum
 

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Discussion Starter · #14 ·
Yes, I used a kit like that and there are indeed combustion gases in the coolant, and coolant in the cylinder. So it is definitely a blown head gasket, or cracked head, or warped block, etc.

Thanks, everyone for the help.
 

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Yes, I used a kit like that and there are indeed combustion gases in the coolant, and coolant in the cylinder. So it is definitely a blown head gasket, or cracked head, or warped block, etc.

Thanks, everyone for the help.
As I said, you can do more testing and get more definitive but for practical purposes, once you can narrow the problem to which bank of cylinders, when you pull the head you will figure it out. Even if you can confirm a coolant leak from the top, you still have to wonder if a lower liner seal is also leaking. You may have to pull the liners anyway to set the "nip" (height of the liners over the top) properly.
David Teitelbaum
 

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Discussion Starter · #16 ·
As I said, you can do more testing and get more definitive but for practical purposes, once you can narrow the problem to which bank of cylinders, when you pull the head you will figure it out. Even if you can confirm a coolant leak from the top, you still have to wonder if a lower liner seal is also leaking. You may have to pull the liners anyway to set the "nip" (height of the liners over the top) properly.
David Teitelbaum
It's definitely the right bank (passenger side).

I didn't see any oil in the coolant or vice versa, but you're right - some testing or inspection will be needed to determine if the liners failed too. Hopefully not since it is the new Hylomar sealant.
 

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As I said, you can do more testing and get more definitive but for practical purposes, once you can narrow the problem to which bank of cylinders, when you pull the head you will figure it out. Even if you can confirm a coolant leak from the top, you still have to wonder if a lower liner seal is also leaking. You may have to pull the liners anyway to set the "nip" (height of the liners over the top) properly.
David Teitelbaum
David,
FYI, the liner "nip" on the 918 is actually below the deck of the block (.003-.004") as opposed to over the top...:)
 

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It's definitely the right bank (passenger side).

I didn't see any oil in the coolant or vice versa, but you're right - some testing or inspection will be needed to determine if the liners failed too. Hopefully not since it is the new Hylomar sealant.
I doubt the Holymar sealant failed at the base of the liners, more than likely one of the liners was either too low or one is too high (this was a new to you block right?) causing the HG failure. pay close attention to liner nip once the head is removed.
Probably best to do with the engine out as I don't think correcting can be done with the engine in situ.
 

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Discussion Starter · #19 ·
I doubt the Holymar sealant failed at the base of the liners, more than likely one of the liners was either too low or one is too high (this was a new to you block right?) causing the HG failure. pay close attention to liner nip once the head is removed.
Probably best to do with the engine out as I don't think correcting can be done with the engine in situ.
Yes, new to me block. Thanks for the nip info - that could be it.
 

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Wingless Wonder
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Hi Mike!

Long time no see....since when have you been working on Esprit V8s?

(For those who don't know, Mike's work is LEGEN-DARY for 4 cyl Esprits and Rover-Engined Elises)
 
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