Coolant leaks due to cracked head or gasket?

GreenDieselEngineering · **Joined:** Sun Jun 07, 2009 5:10 pm **Posts:** 1111

We have been hearing a few higher mileage CRDs with cracked heads or leaking head gaskets. It would be nice to have confirmation from those that had this happen if the problem was the head or just a leaking gasket?

This engine has a multilayer steel head gasket, which is about as robust as it gets. The head bolts are "torque to yield", it could be possible these are stretching or losing torque over time from vibration. It would be helpful for those that need to pull the head to check the "breakaway" torque on all the head bolts.

Also, if someone has a cracked head sitting around we would like a couple to cut apart for analysis. Thanks in advance for the feedback.

racertracer · **Posted:** Thu Feb 16, 2012 3:01 pm

GDE, I have the old bolts in storage, do you care to have those checked and if so how do I go about testing them?

GreenDieselEngineering · **Joined:** Sun Jun 07, 2009 5:10 pm **Posts:** 1111

The head bolts must be check when you loosen them and it does require a very large torque wrench. I think their will be a lot of variablity in the length of a used bolt since they are stretch when initially installed.

geordi · **Posted:** Thu Feb 16, 2012 5:52 pm

Any chance of swapping from those stretch bolts to actual studs like from ARP? I did that on my Jetta when it was being difficult to start (injection pump seal) and it DID seem to help and both make it easier to start, and gave a little better running performance. Could have just been my impression / placebo effect, but at 150k miles, I figure the extra clamping force might have helped compression just a little bit.

racertracer · **Posted:** Thu Feb 16, 2012 6:35 pm

There's an interesting older post on here, about a member experiencing head gasket problems. He decided to solve the issue by just re-torqueing the existing bolts and experienced no issues months later. The post maybe 4 years old and I've given up trying to find it, the search feature on this forum leaves a lot to be desired.

I would have liked to have inquired about how the repair worked out.

BlackLibertyCRD · **Posted:** Thu Feb 16, 2012 7:04 pm

GreenDieselEngineering wrote:

We have been hearing a few higher mileage CRDs with cracked heads or leaking head gaskets. It would be nice to have confirmation from those that had this happen if the problem was the head or just a leaking gasket?

This engine has a multilayer steel head gasket, which is about as robust as it gets. The head bolts are "torque to yield", it could be possible these are stretching or losing torque over time from vibration. It would be helpful for those that need to pull the head to check the "breakaway" torque on all the head bolts.

Also, if someone has a cracked head sitting around we would like a couple to cut apart for analysis. Thanks in advance for the feedback.

I had many head jobs in my shop with torque to yield bolts and I can tell you that once you overheat the engine they will stretch. After that there isn't enough torque to hold combustion from passing the head gasket including the multilayer steel that has very low tolerances of loose head bolts. The torque to yield bolts are never to be re-torqued and must be replaced with with new head gasket and what other part that gets damaged. Moral of the story, if the engine is overheating don't drive until the problem is solved.

grywlfbg · **Posted:** Thu Feb 16, 2012 8:57 pm

There's a long thread on this here:
viewtopic.php?f=5&t=62047

I'm dealing w/ a coolant leak due to a warped head @ 95k miles. Head has already been pulled so I can't offer any bolt analysis. Do you want cracked heads or would a warped head do?

grywlfbg · **Posted:** Thu Feb 16, 2012 8:59 pm

BlackLibertyCRD wrote:

I had many head jobs in my shop with torque to yield bolts and I can tell you that once you overheat the engine they will stretch. After that there isn't enough torque to hold combustion from passing the head gasket including the multilayer steel that has very low tolerances of loose head bolts. The torque to yield bolts are never to be re-torqued and must be replaced with with new head gasket and what other part that gets damaged. Moral of the story, if the engine is overheating don't drive until the problem is solved.

Could you just get new head bolts, drop them in, and torque to spec?

geordi · **Posted:** Fri Feb 17, 2012 2:23 am

Yes. That is what I did on my Jetta (no it never had a coolant leak) and replaced the stretch bolts with ARP studs without ever removing the head.

You do the job one bolt at a time, following the torquing guidelines for the pattern. I would pull one at a time and load in the replacement, tighten to half-load or so of the torque rating to apply SOME clamping force, then move onto the next one. Once all are replaced and half-torqued... Then start following the pattern to fully lock them down.

What you don't want to have happen is that the clamping force loosens unevenly, which can lead to minor shifting in the position of the gasket and it's seal on both surfaces. This is a minor point, but the whole idea is that this thing remains completely flat and never moves from its original position and grip on the seal.

LMWatBullRun · **Posted:** Fri Feb 17, 2012 1:39 pm

Does anyone know offhand if ARP make studs for the 2.8 VM CRD? I know they do for lots of other motors, but I have not checked with them. If they do, I am inclined to go ahead and get a set.

papaindigo · **Posted:** Fri Feb 17, 2012 2:36 pm

According to their current on-line catalog no they don't which is not to say they cannot or will not if there was interest. FYI the catalog is a bit odd as "diesel" stuff is listed under Diesel as if that's the vehicle brand.

geordi · **Posted:** Fri Feb 17, 2012 2:59 pm

ARP studs for my Jetta were (IIRC) listed somewhere like for a Chevy Vega or something random and hard to find... They found it in their own files without a problem, so it is possible they know more on the phone than their internet site has.

RacerTracer tried getting some for his, I think he said they needed measurements of each of the holes in the block for depth and thread count, and mounted length with the head in place. Studs are also different b/c you thread them in finger-tight to the block, then you are ONLY torquing on the nut that threads onto the other end. I haven't looked at my spare to see if that would even have enough room for a nut like that, but I'm guessing it would.

Somebody who is in the process of disassembling their head could call them and they would walk you through the process to get the measurements - They wouldn't necessarily need to manufacture anything for us, there aren't that many styles and lengths of bolts to choose from... Chances are extremely great that something similar would fit.

WolverineFW · **Posted:** Fri Feb 17, 2012 5:29 pm

It thought one person on this site several years ago had ARP headstuds.....I cannot remember who though.....

Edit: Ok found one former CRD owner who apparently had some...

http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=57808&start=40

HugeKJ05 wrote:

When I rebuilt the top end of my CRD I sent everything out to be cleaned, the head was also freshened up and went back together with ARP head studs that I had to specifically spec out to ARP. The ARP studs are probably the only reason the head didn't blow sky high off the block when the Jeep was pushing 40 psi for a few weeks.

ATXKJ · **Posted:** Sat Feb 18, 2012 2:54 pm

To GDE - mine had the Head replaced under extended warranty at 70,000 miles

It had ~ a dozen #2 Glowplugs die - about the 3rd one STAR said change all 4 - they broke one in the head - pulled it and still kept killing 5 or 6 more glowplugs - they went back later and pressurized the radiator overnight - the next morning the GP was wet with antifreeze - so the put on a new head.

it never overheated and warranty decided it was a manufacturing defect.

and while it was having GP problems - it used about a 1/2 cup of antifreeze a month........

e010584 · **Posted:** Fri Apr 05, 2013 4:56 pm

Looks like I'm the latest victim at ~140K miles. #2 GP went long ago and started to hydro-lock cylinder. Ran it longer than I should of in this condition and now have a bad clacking. Any pointers including insight on the ARP studs would be more than welcomed. Hopefully I'll get the head off this weekend to find out how much I'm in for.

geordi · **Posted:** Sat Apr 06, 2013 12:01 pm

You are in for a fix of the bottom end, most likely. These engines don't like cylinder pressure problems. If you don't find an obvious source for the noise on the top end (say a broken rocker on that cylinder) then you will need to look to the bottom end.

Good luck.

e010584 · **Posted:** Sat May 11, 2013 8:37 pm

The head is definitely cracked between the adjacent intake and exhaust ports. There's signs where the broke GP smacked the head a few times but no signs that it is cracked in those spots.

As far as the noise, I haven't pulled the pan yet to verify any other problems, but the harmonic balancer appears to be the likely culprit of the noise with the plastic sleeve broke up in many pieces. This was also the location the noise was emanating from.

Right now, I'm looking for head options as the weld repair doesn't look that great - removing the seats, grinding out the affected area, building up the new material, machining, pressing in the seats and grinding.

LMWatBullRun · **Posted:** Sun May 12, 2013 3:37 pm

e010584 wrote:

The head is definitely cracked between the adjacent intake and exhaust ports. There's signs where the broke GP smacked the head a few times but no signs that it is cracked in those spots.

As far as the noise, I haven't pulled the pan yet to verify any other problems, but the harmonic balancer appears to be the likely culprit of the noise with the plastic sleeve broke up in many pieces. This was also the location the noise was emanating from.

Right now, I'm looking for head options as the weld repair doesn't look that great - removing the seats, grinding out the affected area, building up the new material, machining, pressing in the seats and grinding.

I'd look around for a used head. Keep in mind that a trashed engine is likely to be rockers not affecting the head materially......

audiboy86 · **Posted:** Sun May 12, 2013 5:33 pm

Blown head gasket here and all the bolts were at a different torque spec some were really high others were low only a handful were even close to the proper spec. I have never over heated this motor I have eased about a tick of the center mark but the was years ago.

LMWatBullRun · **Posted:** Sun May 12, 2013 6:15 pm

audiboy86 wrote:

Blown head gasket here and all the bolts were at a different torque spec some were really high others were low only a handful were even close to the proper spec. I have never over heated this motor I have eased about a tick of the center mark but the was years ago.

still more confirmation of the need for more reliable head clamping, and more bearing surface from bolt to head. Audiboy86's experience is very similar to mine.

Coolant leaks due to cracked head or gasket?

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