A couple years ago I had a slight head gasket leak by the thermostat housing and ended up over torquing the head bolts by 5 or 10 ft lbs to stop it. Not exactly a smart move I know but was in a bind, 3 hours from home, and trying to leave a location. 

 

A lot of things have happened since then and I smooth forgot that I ever did that until I noticed a water leak today. It's leaking from the exact same spot as before so I see a new head gasket in my future. 

 

Now I've read a buch of different things about the cause of a leaking HG including a cracked or warped head, both of which would suck. With 300k miles on the truck how likely is it to be something serious like a cracked or warped head? I'm wanting to be as prepared as I can to minimize downtime once I'm ready to pull the head.

 

I'm planning to have the head resurfaced, check the valve seats and grind them if necessary, replace valve seals, and install head studs and 60lb valve springs.  

mouser has most all plugs.  

 

ECT plug

http://www.mouser.com/Search/ProductDetail.aspx?R=12162193virtualkey63000000virtualkey829-12162193

@Me78569 Thanks!

 

We'll the two manifold bolts that broke off would not come out after applying heat and using an easy out. So, I'm drilling it out and using longer bolts with nuts. 

 

The valve guides don't have any play whatsoever, awesome. I'm about to do a light lapping with some fine clover compound.

Yay or nay on the exhaust valves?

 

 

ETA: Answered my own question, they leak 

 

ETA #2: After 20 minutes lapping the leaking valve I just about have it sealed up. It would be a lot easier if I had something stouter than fine lapping compound  I'll be picking up some medium and corse compound tomorrow.

Edited July 20, 20168 yr by The_Hammer

Doesn't look horrible,  I'd use it. I say that now but if I had mine out I'd be taking it to the shop for a valve job decking cleaning and magnaflaxing to be sure. But at the same time it ran fine before. Depends on how much money you don't need. 

@Dieselfuture The head has been cleaned, pressure tested, and resurfaced. In a perfect world I'd have a valve job done but I'm running out of funds for this, especially since I'm still working on my house. 

As for the block flush, it list here on M73M.com in an old post. The product is a clear liquid sold in a round 1-gallon jug and more or less a plain white label if I remember right. It's a pretty stout chemical being it will remove rust and scale build-up from the entire cooling system. It's actually designed for engines. If I'm not mistaken Cummins sells it. (IIRC...)

Edited July 20, 20168 yr by Mopar1973Man

13 hours ago, The_Hammer said:

Yay or nay on the exhaust valves?

 

 

ETA: Answered my own question, they leak 

 

ETA #2: After 20 minutes lapping the leaking valve I just about have it sealed up. It would be a lot easier if I had something stouter than fine lapping compound  I'll be picking up some medium and corse compound tomorrow.

The valve itself looks good! Not sharp on the edge, no deep grooves, etc. Assuming the stem looks good and you can get them all sealed up you should be good to go!

2 hours ago, The_Hammer said:

Last pic isn't working for me...

Also, I would use a wire wheel (if available) to clean the carbon build-up off of them. A wire brush would probably work too.

@TFaoro I only posted two pics, don't know what the third one that's not showing up is about . I got the majority of the carbon off before installing the valves.

 

Finally got all the valves to seal, only took most of the day to do it lol.

Finally got her back together today. I was losing a LOT of compression from the leaking exhaust valves, my turbo sounds completely different now, like a normal HX35. It's never sounded like other 12v trucks until now. The power has increased quite a bit as well, it's VERY noticeable to say the least. It idles smoother and just sounds better too. I'm also happy to finally have a 4k GSK, now the truck pulls hard all the way to 3800 rpm or so.

 

I'm running without a thermostat for now while I flush the rust out of everything. I'm going to order some Evaporust Thermocure to try and flush it all out. Once I'm done I'll be filling with 50/50 premix, which brand I'm not sure yet

Edited July 23, 20168 yr by The_Hammer

My starter isn't liking the extra compression, guess it's time to rebuild it