Jump to content
  • GUESTS

    If you want access to members only forums on HSO, you will gain access only when you Sign-in or Sign-Up .

    This box will disappear once you are signed in as a member. ?

Where would my coolant go?


Recommended Posts

92 Chevy C/K V6 A/C but I don't use it. In the last 6 weeks I have had to put in a full bottle of coolant. I don't see any obvious source of a leak, no puddles on ground or on hoses.

I drained and replaced the oil and it seemed normal.

Could it just be a slow drip only when I am driving? My temp gauge never alarms or anything.

Link to comment
Share on other sites

The usual culprits are the intake gaskets and water pumps. If your not noticing it than it is probably only leaking when its hot. Look in the corner if the intake gasket where it meets the head on the front of the engine. If its leaking it will usually leave a trail.

There are three options, Wait for it to get worse, Pressure check the cooling system (both hot, cold, engine running, engine off), or add die to the cooling sytem which will make the leak easier to spot.

Link to comment
Share on other sites

my 97 Chev 1500 is losing coolant slowly also. about a half jug every 3,000 miles or so. I re-did the water pump last winter, the oil is always fine when i change it, i dont know where its going, i dont care at this point (231,000 miles), i just check it when i change the oil and add. at least its not burning oil!!!

Link to comment
Share on other sites

Many 4.3 V-6s, 5.0 and 5.7 V-8s share the same problem with the intake gasket (though the later ones were no where near as bad as 5 years earlier). GM aluminum intake manifolds on cast iron heads have very different rates of expansion and have a lot of 'creep' over the gasket. The gasket will crack because of the head/intake manifold sliding across it. Many times the leak starts very slowly and is internal - leaking coolant slowly into the valley - directly to the crankcase. Even slowly enough that engine heat will evaporate the water faster than make the traditional brown mess of water in the oil. A tell-tale of this - check the dipstick: if the upper end of it has water droplets or is rusty you may have this problem. As it gets worse the gasket then cracks at the ends causing a trail at the front or rear of the head.

When repairing ONLY use the best / most expensive intake gasket you can find - more layers, better bonded silicone rubber traces, etc. These will tolerate the creep better and last longer.

Originally GM used paper type gaskets here, the later years they changed to the better multi-layer gaskets.

The slow internal leak causes additional problems. The ethylene-glycol left behind in the oil causes acid buildup and premature crank, rod and bearing wear. I recommend also doing an engine flush to finish the job.

Link to comment
Share on other sites

Yup, I agree completely with intake gaskets.

Replaced intake gaskets on my 1994 with some McCord gaskets from one outfit and when it leaked again a year or two later, and the gaskets were super crusty upon disassembly, I decided enough of that. Second time I used some somewhat more expensive Fel Pro gaskets with the seal stuff like theoilman described and haven't touched it since. Probably been at least 5-6 years now, I'd guess, and no signs of any coolant loss.

And yes, it was all done per the factory service manual, including torque wrenches, etc.

Link to comment
Share on other sites

Check your gaskets. Water pump gasket? Intake gasket? I had the same problem and it has been fixed with a new water pump gasket. It only leaked when the engine was hot. And it dripped into my skid plate so I never saw any coolant on the ground. I think it is pretty common on older trucks that don't get used a lot and sit for a period of time.

Link to comment
Share on other sites

its getting pressure tested today, anything from lower hose to the gaskets. Quote on gasket was 600. The temp gauge just flies all over the board no reason to it, on a cold engine start it flips over to above 260 then will just swing back and forth. Gotta love the classic vehicles grin

Link to comment
Share on other sites

glad to hear it was something less serious. My sons '96 S-10 Blazer had a bad intake gasket as everyone mentioned and cost us $600.

It's not a question of if it happens, but WHEN it happens I would recommend what theoilman said about flushing out the entire engine.

Link to comment
Share on other sites

ya, this is just one of those vehicles that I plan to own until it rusts apart or blows up, and it was all flushed out laugh

Related to this though- I haven't had any reason to discredit the mechanics so I believe them but riddle me this. Did this before during and after the radiator change and flush. The temp gauge just jumps all around with no rhyme or reason to it. I can start it up in the morning and the gauge will go all the way 260+ then will just swing back and forth, may settle down to below 110 jump back a few minutes later, on and on you get the pic. The mechanic said just probably just a messed up gauge because the cooling system is fine, unless I want to pay more $ to have them really look into it, which I said no. There is no change in the sound or tone of the engine at all.

Any ideas?

Link to comment
Share on other sites

Join the conversation

You can post now ↓↓↓ or ask your question and then register. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.



×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use and Privacy Policy. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.