Head cracked...

[J20]

I had thought my engine was entirely seized because it would not crank. Following a friend's suggestion, I pulled the glow plugs and tried cranking it. It spat out water from no. 4 cylinder and turned freely, so I took that as a hint that the jeep ain't as dead as I thought.

Cue half a day of spannering and skinned knuckles and the head is off. It looks to me like the head at no.4 cylinder has been cracked and leaking for a while going by the pitting and the size of the crack. The head is cracked on all 4 cylinders but no. 4 is far more noticeable than the others.

My question are these:

when I had my "incident" where I forgot to put the coolant cap back on, I pulled in to a petrol station and there was water coming out the tail pipe and the coolant was blowing out the filler spout. Would the cracking explain that? (along with the excess heat from loss of cooling)

Also: how can I tell if the block/pistons/etc is ok? There's no mayonnaise anywhere and the bores look smooth and clean to me. No pitting on the pistons either, not even on no. 4.

Thanks, Dave.

[J20]

A close up of the head at cylinder no. 4

[J20]

The block and pistons

[andyverran]

it occurs to me the rings wont have had a good time being oil free...how far did you drive it knackered?

[BUSHWHACKER]

Jeep???

[Growler]

Jeep???

Yup, his Surf is fine , but he broke his "Jeep"

[J20]

Jeep???

Over here anything approximately jeep shaped is called a jeep.

There's plenty of oil in it - how would it have been oil free? To answer that question, I drove about 10 miles before it started making puffs of smoke and that's when I stopped. I can't say how much of that was after the head blew.

[muddle]

Check for piston float, wiggle side to side etc to check the rings and shine a touch down past them to see if there's any noticeable gaps, then check all 4 pistons reach tdc at the same height to make sure a hydrolock hasn't bent a con rod.

If all passes, fit a new head.

[andyverran]

Over here anything approximately jeep shaped is called a jeep.

There's plenty of oil in it - how would it have been oil free? To answer that question, I drove about 10 miles before it started making puffs of smoke and that's when I stopped. I can't say how much of that was after the head blew.

Lots of water in the cylinder will wash oil off...

[J20]

Thanks for all the replies!

Sorry about calling it a jeep. I have three jeeps: the Surf, a Frontera with no front diff (for another day...) and an old american hunk of junk pickup actually made by Jeep.

I'm hoping I've got away with the block being ok. I stopped the engine by turning off the ignition rather than it stopping itself. It just wouldn't turn over afterward. So it didn't hydrolock under power and shouldn't have had the shock loading on the con rods. I'll be checking the TDC heights anyway.

The bores look nice and smooth to my eye with no scoring that I could see.

I can shine a torch down the side of the pistons easily enough but how do I check the float? Is it a matter of using feeler gauges to measure the gap to the bore?

[J20]

Lots of water in the cylinder will wash oil off...

That makes sense. Hopefully not enough water for that...

Would this show up by checking visually, ie: the torch down the side of the piston/bore?

[andyverran]

This might be useful:
http://www.youtube.com/watch?v=iYpzeVNcEG4

I'll have a look for more...

This is for a bike, but still looks informative:
https://www.youtube.com/watch?v=hdTW_RBR3Aw

[24overheat]

Id be very surprised if theres con rod damage with a hydro locking on your engine,i personally with many years experience have only seen it happen on an engine that swallowed alot of water in the intake after going through a deep puddle, at high revs.No harm to check tdc though,if ok,fit replacement head and new gasket and change the sump oil and filter.These heads usually always crack after theyve heated up too much,having already been skimmed in the past.Warp first time,crack second

[J20]

The repair: questions before I start

I have finally placed my order for a new head, bolts etc from Roughtrax and I will be fitting it in my spare time over the few weeks.

I obviously want to avoid having to go through all this again, so any tips before I get spannering? Also, any other jobs that are worth doing that are easier with the head off, I will seek to do as well.

Things that I am planning:
- replace thermostat
- coolant level alarm with buzzer (adapted from this one)
- vdo type temperature gauge
- egr removal. It's in pieces from removing the head, so it would be silly not to.
- remove bonnet rubbers
- I have a trooper bonnet scoop lying around so I was considering putting it on and cutting a big vent in the bonnet
- viscous fan oil upgrade
- oil and filter change

Would a block mounted or head mounted temperature gauge be of any value? I found this on ebay and it set me thinking. Where would it be best to mount it to get useful information?

Is there anything worthwhile that can be done with the injectors before I swap them in to the new head? I was planning on getting them tested but is there an upgrade?

Thanks in advance!

Dave.

[tashtego]

I have finally placed my order for a new head, bolts etc from Roughtrax and I will be fitting it in my spare time over the few weeks.

I obviously want to avoid having to go through all this again, so any tips before I get spannering? Also, any other jobs that are worth doing that are easier with the head off, I will seek to do as well.

Things that I am planning:
- replace thermostat
- coolant level alarm with buzzer (adapted from this one)
- vdo type temperature gauge
- egr removal. It's in pieces from removing the head, so it would be silly not to.
- remove bonnet rubbers
- I have a trooper bonnet scoop lying around so I was considering putting it on and cutting a big vent in the bonnet
- viscous fan oil upgrade
- oil and filter change

Would a block mounted or head mounted temperature gauge be of any value? I found this on ebay and it set me thinking. Where would it be best to mount it to get useful information?

Is there anything worthwhile that can be done with the injectors before I swap them in to the new head? I was planning on getting them tested but is there an upgrade?

Thanks in advance!

Dave.

Hi Dave, I am going off topic a bit.
I'm genuinely interested in why you and other members are investing so much time and money on keeping the 2L - TEs alive.
Don't get me wrong, I think most of us on the forum started with a 2.4, but now that the 2nd Gen 3.0 L are available (and very cheap in UK!), why bother? The heads go again, they are painfully under powered...and thirsty. The 2nd Gen KZ-TE is not perfect but miles better. The mods you have on your 2.4, if any , can be swapped over to the 3.0 L.
Is it kind of an act of "mechanical defiance", to keep alive an icon, a cult car? A bit like people repair old beetles etc, like a "classic car" sort of thing?
Over here the 2.4 has gone the way of the Quagga or the Dodo. Darwinianly weak and therefore extinct.
I know a lot of the Aussie guys also love their 2.4s, they fit them with all sorts of Temperature sensors. But isn't it a bit stressful driving around with an eye on the gauges,hoping that the thing doesn't cook again?
Genuinely interested.
Good luck with your head fitting.