• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

cracked head...but cracked block too?

StylerG

StylerG

NAXJA Forum User
Location
Oklahoma City
2000 xj (220,000 miles)
dry compression (1-6) 150,150,140,150,155,160
coolant pressure test shows coolant leaking into all cylinders
head gasket looks fine, milky oil after a severe overheating after complete loss of coolant.
Pretty sure the head is cracked, but worried that the coolant leak could be somewhere in the block causing the initial loss of coolant with the head cracking after the overheating....any clues or advice on this?
 
I bought my 96 cheap because it "overheated and needed a head gasket". When I pulled the head I noticed the injector harness where melted to the head bolts. Pulled the head, it was cracked and put my spare head on. It ran good, but I was loosing coolant and throwing codes to the CIL.

Finally swapped in the 99 engine out of the 89 XJ and it runs great now. When I tore the old engine down, there was a crack in the block between two of the cylinders. So yes, they can crack if they get really hot.

If you haven't pulled the head yet, that's where you should start. Pull it and have it checked. With 220,000 miles, rebuild the head if it's good. You could always go shopping for a low milage engine.
 
i have the head pulled already, just giving you the numbers from when it was on. My concern is the coolant in all cylinders, with a head gasket that looked to still be good. Anyone else on this?
 
How did you pull the head. i might have to do mine soon to rebuild it. Is there a step by step how to some where. Ive never done it before but I want to learn how.
 
StylerG said:
i have the head pulled already, just giving you the numbers from when it was on. My concern is the coolant in all cylinders, with a head gasket that looked to still be good. Anyone else on this?
Click to expand...

Did you have the head checked? I'm thinking head or head gasket. I think it would be very rare to get a crack across all six cylinders in the block.
 
the head is off to be checked. I just wanted assurance that when the head comes back cracked (im 99% sure it will) that i wont be putting a new head on a possibly cracked block.
I didnt think it was normal for a cracked head to be seeping coolant through all cylinders...but it really sounded strange for a block. Just wanted to make sure before i went ahead with anything.
 
Rich_1833: Go to the library, make some photocopies, or purchase a manual at your parts store, or try to find a service manual specifically for your year on eBay, etc.
 
Last edited:
StylerG said:
2000 xj (220,000 miles)
coolant pressure test shows coolant leaking into all cylinders
Click to expand...

I'm not sure I'm following you on this one. If you pressurize the cooling system are you using some kind of borescope to look into each cylinder and seeing a leak? What indicators are you seeing that its leaking into all the cylinders?

The other tell is that the cylinder(s) would be free or carbon inside and the spark plug porcelan would be nice and white from the af/water being mixed in.

I'd also take a good straight edge and lay it across the block deck both length and width wise at numerous points and check with feeler gauges for warpage.
 
wheeling365 said:
I'm not sure I'm following you on this one. If you pressurize the cooling system are you using some kind of borescope to look into each cylinder and seeing a leak? What indicators are you seeing that its leaking into all the cylinders?

The other tell is that the cylinder(s) would be free or carbon inside and the spark plug porcelan would be nice and white from the af/water being mixed in.

I'd also take a good straight edge and lay it across the block deck both length and width wise at numerous points and check with feeler gauges for warpage.
Click to expand...
and diagnolly
 
jeeperjohn said:
Since this thread is 4 years old, I would guess the OP probably fixed it long ago.
Click to expand...

Correct! I had to look twice at this to really believe someone brought it back up. Had the head magnafluxed and decked. Once everything was assembled again sure enough one of the water passages in the block was cracked.
 
You must log in or register to reply here.

Similar threads

B
Reasons for white exhaust smoke besides head gasket?
Replies
1
Views
823
RCP Phx
R
C
Before I Get the Head Milled (Overheating)
2
Replies
31
Views
8K
maxbraketorque
M
M
Oil pressure question
2
Replies
26
Views
3K
Money_Pit_Incoming
M
E
95 XJ Overheated, Shop says Head Gasket, need advice/info
Replies
18
Views
3K
Etherel15
E
K
96 XJ 4.0 LOW COMPRESSION QUESTION
Replies
6
Views
3K
Evan03
E
Back
Top