hard rad upper hose

[matuva]

I know that when you get a blown headgasket or a cracked head, the upper hose from T-stat to radiator gets hard when you run the engine.

Do you have the same symptom when you get a cracked block?

I was wondering that, because on the 97 K1500 of my father in law, we did the heads.
We found water inside cyl #8, and so had the head tested. The head is supposed to be good, but unfortunately, after we put everything back, we had to face stumbling engine with white smoke, hard upper hose, and ... hydrolock---:mad2:
Obviously, something is cracked. Wonder wether it is the head or the block

 

[jmiller]

Bubble Test

I've used the "Bubble Test" to narrow down a compression leak.

• Remove the Serpentine belt and Thermostat's
• Top off the coolant until it can be seen in the thermostat housing.
• Momentarily start the engine, watch the housing for bubbles. Run the engine for no longer that 30 seconds at a time.
• If a side produces bubbles, the offending cylinder can be determined by:
  
  [*]Pull a glow plug from the suspect cylinder
  [*]Start the engine and watch for bubbles to slow or stop. Run the engine for a very short time, less than 15 seconds.
  

  [*] Remember, you are pumping raw fuel in to the cylinder and out the glow plug port. Take appropriate protective action.
  [*]The engine will also run ruff
  [*]Get help for this step if you can
  ​

  [*] To confirm a cylinder to cylinder leak, pull an adjacent glow plug.
  

  [*]The engine will run very ruff and it will be difficult to determine if bubbles are present in the thermostat housing​

This test will help narrow down the focus in determining the root cause of a compression leak caused coolant loss issue. I used it to verify that a cracked head that had been hot pressure tested was actually leaking.

 

[iamdave0887]

do you have oil in your coolant or coolant in your oil? if you've got coolant in your oil the bearings will be toast fairly quickly. i know that you can tell if you've got coolant in your oil by the milky coloring you'll get from the mix and the oil level will rise.

 

[matuva]

As far as we can see, no oil in coolant, and no coolant in oil, just hydrolock at cyl #8.

What we are not sure is if it is a head or block crack---

 

[just a number]

I blew apart the head gasket in mine. no mixing of fluids. all it did was dump the coolant into the reservoir all the time.

 

[North Maine]

the number 8 cylinder is known to develop pin holes in some blocks that leak in coolant when not running and then pressurize the coolant system when running... the only fix and another block... although apparently there is a *maybe* fix that is a powder available from GM that is ginger root based that fills in the holes?? There was a site all about this issue i read a couple years back.

 

[Diesel -T]

There was also quite a lot of discussion on a couple products on the other site a couple or so years back ,"steel seal" or something to that effect. Quite expensive & fair bit of work involved in using .Dont know if they were successful in high compression Diesel engines or not.

 

[jmiller]

The GM ginger root does not work the best on compression leaks. It works best on leaks to lower pressure areas, like external block and radiators. It did not work in my truck.

Most sealing products will have problems on diesel compression leaks into the cooling system.

good luck

 

[matuva]

I note that hydrolock happens fast : after the engine has run for a while, then shut off, it takes no more than 5 mins for hydrolocking.

 

[Acesneights1]

Try the GM cooling seal tablets. I had a 6.2 that was burning antifreeze so bad you couldn't drive it. I put two packages in and the smoke was gone in less than 10 mins. I drove the truck 3 more years and was still holding when I sold it. You got nothing to lose at this point. The alternative is a new engine. This is not hear say I heard. This actually worked for me. It has to be the GM stuff. It was designed to seal the blocks on those junk aluminum engines they used in the caddys IIRC.

 

[matuva]

that could be an alternative.
Any idea from where I could find these tablets?

 

[Diesel -T]

Dealer should be a source.

 

[matuva]

no more dealer in New Caledonia selling US Chevy trucks at the moment---

 

[North Maine]

mmmm i'll be up home this weekend, I think they're open on saturdays? I'll try to grab some and ship them out to you, if that is at all possible? how much does it cost to send an envelope to New Caledonia?

 

[Gunner0812]

mmmm i'll be up home this weekend, I think they're open on saturdays? I'll try to grab some and ship them out to you, if that is at all possible? how much does it cost to send an envelope to New Caledonia?

Let me if they dont have them and I'll check in my area.:thumbsup:

 

[North Maine]

I did some digging on another site I'm a regular on, I inquired about 6.5 issues a LONG time ago, and this was something that came up, I checked the link and it still works.

http://flashoffroad.com/Diesel/No8Cyl/CrackedBlock.htm

This *might* be what you are looking at.

 

[North Maine]

GM part #: 12378254

"Cooling System Sealant Tablets"

That's what that page recommends, I dont know if its the solution, I havn't heard a whole lot about it in these C/K forums.

 

[JeffMD]

Possible issue with the sealing tabs.
I threw some in my truck a while back to deal with an external leak at the water pump until I have time to deal with it. It only leaks intermittently now, but I now have a problem with one of my thermostats apparently not closing all the way. There are some days when it takes forever to get that temp needle to move.

 

[North Maine]

I have that issue too, but i think its a bum t-stat... good point though... but I dont know which is worse, I'm pretty sure New Caladonia is a pretty warm place, so maybe that wont hurt a thing!!

 

[matuva]

mmmm i'll be up home this weekend, I think they're open on saturdays? I'll try to grab some and ship them out to you, if that is at all possible? how much does it cost to send an envelope to New Caledonia?

Thanks for the proposal. I think sending em in an enveloppe should be around $15.00 express mail.
Anyways, PM me and I will Paypal you the money.

Let me if they dont have them and I'll check in my area.:thumbsup:

Thanks too