The head gasket on my '99 3500 is seeping coolant to the outside at the corner of the block that's immediately below the thermostat housing. I'd say it leaks about two drops every fifty miles, so I'm not concerned about the loss of coolant. But I am somewhat worried that the gasket could also be leaking coolant internally, though I've seen no evidence of coolant in the oil. Do you guys think this is something that should be repaired now, or should I hold off until I require some further engine work? The motor has 235K on it. Thanks!!!

 

I have a 12v but mine did the same thing as what you descibed I changed mine and looked at the gasket its self and it could leak to oil passage but darn near impossible id say. Chances are it is just ate away at the outside of the gasket enough overtime that it can weep a little when it is hot Did mine at 185k or so. Just my two cents

 

The upgraded head gasket has extra sealing in that area.
When you get ready to change the gasket, get an engine hoist because the cylinder head weighs near 200lbs.

 

I am in the process of completing this job for exactly the same reasons. My leak started the same as yours, slow but then this spring on the way back from Florida I was going through a gallon of coolant every couple of hundred miles or so. I wanted to make sure that I'd not have to do this again so I looked for the best head gasket. I contacted Cometic three weeks ago and they no longer have a head gasket for the 5.9. My local stores could not find a FelPro but they did find a Victor. The best price for the Victor was $129. I choose to go with the updated Cummins upper engine gasket package part #409 0035 which includes the latest and greatest 3977 063 head gasket along with gaskets for the intake, exhaust manifold, turbo, valve cover as well as the valve seals. Compared to the old one, the replacement gasket does have additional sealing material around the area of the thermostat housing. Hope it works.

I Googled the Cummins part number and found a few places that had the gasket kit. I got it on e-Bay for about $200, which isn't cheap. Cummins said to install the gasket dry so that's what I did. Hope it works.

The Cummins upper engine gasket kits does not include the injector o-rings or copper washers. The injector o-rings are metric and I could not find them here locally except at the dealer store and they wanted a little over $6.00 for each o-ring. One o-ring for each injector, one for each transfer tube and the copper washer for the injector was another six bucks. Thats about twenty bucks for each cylinder just to seal the injectors - - way too much for me. I passed on that and decided to use the old ones since they look fine to me.

I decided to do all the belts and hoses as long as I had the engine down. I was not aware of it when the engine was running but the bearings in the serpentine belt tensioner were shot (growling and rough) as was the bearing in the a/c compressor tensioner. I removed the serpentine tensioner pully and one of the bearings (there are two) in the tensioner pully just fell apart in my hands. I have a motorhome and the accessory belt drive is a little different than on the Mopars - - I have a serpentine belt for the water pump and alternator and a separate v-belt for the a/c compressor. Both tensioner pullys are steel and have retainer snap rings that after being removed, allows the bearing to be driven or hammered out - quite simple really. I was lucky that I decided to replace them because they'd have failed in the next hundred miles anyway. The bearings I got locally are National #203-FF (plastic grease seal) and #203-SS (metal grease seal). There were about eight bucks at the local parts store. If you want to use a different brand of bearing, the demensions of the bearings are: 17 mm bore, 40 mm outside diameter and 12 mm wide.

Be careful and take it cool in this area. I have an oil proof silicone rubber hose that connects the turbocharger oil return line with a corresponding tube in the oil pan. Like an idiot, I cut that hose off in order to remove the exhaust manifold and turbo. No one in town has this oil proof hose except the dealer. The hose is metric but it is about one-inch id and is about three inches long. Are you ready for this? The cost of the hose at the dealer is $47.00!! I need it, they got it and they know I need it so I ordered it this afternoon - - it'll be here tomorrow.

I hope this helps a little and perhaps saves a couple of bucks for you.

Good luck. Ken B

 

Thanks, GMCMHDRIVER, for taking the time to share all that great info! It's going to be terrifically helpful when I tackle this project.

 

My truck is leaking coolant in this exact same area. I tried (in vain) to retorque the head bolts hoping it would help, but I didn't understand that business in the Haynes manual about "tighten an additional 90 degrees" and my "retorquing" only really applied the second 70 lb foot setting called for in the manual. To get at the head bolts, I had to r&r the rocker arms and shafts. I did at least use the otherwise wasted time to check my valve clearances. They were all good. My truck has about 189k on it now.

I'll be replacing my head gasket soon. All that is stopping me from completing this job is the cylinder head weight and getting one of those expensive engine crane things. I see there is a Northern Tool unit for about 195.00 that I plan to get hold of soon, so at that time I guess I'll take the plunge. It's good to know that the new gaskets have extra material in this area. I wouldn't mind slapping on a set of 12mm ARP studs at the same time I do the head gasket. Supposedly they don't require any machining. Good luck with your head gasket repair. If you want I can keep you posted as to how mine goes. :-)

 

Sorry to hear about your head gasket. I could sometimes faintly smell antifreeze after stopping at a rest area or at a campground ever since I bought my motorhome a year ago with 36K miles on it. It looks like the leak problem might be more age related than mileage. During disassembly for head gasket replacement, I found a second head gasket weepage on the rear of the engine on the intake side - diagnoally across from the one under the thermostat housing. It was very small but it was definitely weeping a little. I've taken some pics of the old head gasket where it was leaking - - I'll post them if anyone wants to see them. I also picked up my super-duper non-gold-plated $47.00 turbocharger drain hose. I got a 25% employee discount but the thing still cost over $40.00. I gots pics of the hose and the dealer invoice if anyone wants to see that as well.

 

i had the same... bars stopleak fixed it , i hope

 

It wont, I tried that. All it did was clog up the heater core.

 

good so far

 

Has anyone sucessfully completed a head gasket replacment without completley removing the head? or is even possible, what are some recomendations for head machine work (if any) while this thing is apart. The leak on my brothers just started so there is hope that there has not been any damage to the head itself. What are the chances of this??

Thanks

MF

 

I used an engine hoist...the head is heavy and has to be removed to replace the head gasket. I had head machined dead flat then spent much time scraping the deck surface of the engine block to give mine the best possible chance of success....been good 2 years now.

 

I have to agree with Clunk - remove the head and clean the gasket surfaces really well. My engine only had about 45k miles on it and the areas where the antifreeze was leaking was kind of "scaley" from evaporated coolant. There was also some BarsLeak residue in those areas. I used a putty knife, then a razor blade scraper and finished the job off with Scotch Brite pads and mineral spirits solvent. I sprayed and wiped both gasket surfaces with brake cleaner just prior to installing the new gasket and head. Again agreeing with Clunk, the cylinder head is heavy - it's also bulky and it's easy to have it bump into things during the remove and install. If I was going to do the job again, I would make some guide pins to allow the head to be installed squarely on the new gasket. You can damage the new gasket if the end or edge of the head bangs into and gouges or scrapes the gasket during installation. My suggestion is to go to the hardware store and buy two 12mm bolts that are a couple of inches longer than the existing headbolts. Cut the heads off the hardware bolts and hacksaw a slot in the end of bolt where the bolt head used to be. Screw these "guide pins" into the block finger tight (or even looser). This will allow the cylinder head to descend squarely onto the new gasket. Then, use a screwdriver to remove the guide pins. For just a couple of bucks you can make sure the gasket is not damaged during the installation. I have a pusher motorhome and it uses an oil-to-water cooler for the Allison tranmsission and the cooler was full of BarsLeak solids - not surprising since I used several large bottles of the stuff on the way home from Florida. Mopars might be different but if you have a similar oil cooler, it would be wise to flush any cooling system sealers that might have settled there. Good luck on your repair. KenB