97 Blazer 4.3 Vortex coolant loss

Coolant -- losing about 1/2 gal every 500 miles - doesn't seem to matter, street or highway.

5000 miles ago (July 08) intake manifold gasket failed, replaced at shop. The loss of coolant is just in the last couple of weeks.

Have checked and can find no sign of where it is going - drive, get it hot, put cardboard undneath, nothing the next morning. No driveability issues. Thoughts?

The coolant is going somewhere.. oh. New radiator about 2 years ago.. no sign of leaks there.. this does have the trans fluid cooler as part of the radiator. No change in level or color of trans fluid. Same for the oil.

Miller

Reply to
Miller
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They had issues with the intake gaskets on that engine. They were redesigned at least once recently too. What source did you use for new gaskets? Typically they leak down back of block by bell housing and my go unnoticed for some time. You could try retorquing bolts on cold engine to see if it helps but replacement is likely needed. Also, you can use a lower pressure radiator cap to slow leak until it is fixed. Stock cap pressure will greatly increase leakage rate.

Reply to
SnoMan

Yes, the shop was aware of that and told me they used the newest redisigned gasket.

OK.. will check. time for tools or trip to a friends. You'd think I would catch something on the cardboard, though - I've done that trick several times and the cardboard is under about the front half of the truck including the transmission.

Ah, that might help. What other issues might a lower pressure cap bring about?

Thanks!

Reply to
Miller

WHose gasket was it though?? (who made it)

Generally if leak is not too bad it will evaporate on warm engine block and never hit the ground. There will be a "dye" trail on back of block from where it has been doing this.

I have run lower pressure caps for many years with not problems. High pressure caps are more for consumers that may not use proper amount of anitfreeze and need pressure to raise boil point of water. (each 1 PSI raises boil point of pure water 3 degrees) Adding antifreeze also raise boil point too. Pure antifreeze boils at about 340 degrees at sealevel pressure. I generally shoot for 60/40 to 70/30 ratios (antifreeze/water) and have done this for years. Radiators and overflow tanks are clean as new and the higher ratio increases boil point enough that added pressure (and strain) on cooling system parts is not needed.

Reply to
SnoMan

You need a good flashlight and a mirror. A cooling system pressure tester would be nice but may not be necessary. Warm it up good and start looking. Look all along the intake, water pump, radiator and any hoses. Inspect them all one at a time. look at every inch don't move on to the next part until you're sure of the one you're checking. Don't just look for coolant, look for traces of coolant residue.

Don't rule out something just because it's new. There are a lot of Chinese composite radiators out there that only last about two years, I've replaced a bunch of them. If the radiator is fairly new and the intake gasket were done just last year I'd vote on a water pump that's going south on ya. You just gotta look, you'll find it.

nobody #1

Reply to
nobody #1

Follow up: Have been tracking coolant useage. This morning poured (very carefully, slowly, using funnel) more in. Puddle starts forming on ground.. this after a 50 mile drive last night.

Water coming out either where lower hose connects to water pump or just above it on the pump, I could not get enough light in there to see 100% for sure.

Hmm. So perhaps the seals on the pump finally changed from a slow leak to a large one (seal finally failed completely) ??

Will be getting it to where I can do more/ see more first of the week.

Reply to
Miller

My Blazer is a 98, also with the 4.3 engine. I did the water pump on my last Blazer, but that was before the Vortex series. Have at it, good luck and all that.

Reply to
Stormin Mormon

Reply to
Meebers

I can't comment on Vortex water pumps. But every water pump I've done has had a hole on the bottom. It's when the rubber seals start to rip and leak. And then the drip hits the fan. (sorry, but I thought it was funny.)

Reply to
Stormin Mormon

GM pumps have holes on top and bottom. When you see ANY amount of leakage at them your on borrowed time. The seals are failing and allowing coolant into the bearings in the pump. Not a good thing.

On the 4.3 the pump is VERY easy to change out. Drain the coolant, while it's draining remove the top half of the fan shroud (don't miss the clip for the front diff. vent on the left side next to the upper hose!)

Now remove the fan and clutch. You need a fan wrench OR a large crescent to loosen the fan, it has a standard thread NOT a left hand thread. Now loosen the bolts holding the pulley on. Next remove the belt. Now take the pulley off and remove the clamp on the bypass hose on the pump end.

Plan on replacing that hose while you have the pump off, it's a BIT%^ to replace if the pump is on. Now remove the 4 bolts holding the pump. When you get the new pump make SURE it is for the 4.3 with a reverse rotation pump. If in doubt cross it with the pump for a 2000, they use the same pump. Now clean off the old gaskets and any crud that you find. Once you have this done put a thin coat of sealant or high tack to hold the gaskets while you install the pump. Use the sealer on the pump side.

Now make SURE you install the bypass hose and pump at the same time, don't forget the clamps!. Install the pump and then reverse the rest of the process to button it back up. When you fill it you will need to burp the system to remove any air. It likes to collect in the core and cause strange noises and heater problems if you don't get the air all out.

To burp it fill it up and then move the vehicle so the right front is setting higher than the rest of the vehicle, I like to use a handy bank next to the shop but a high curb or ramp would work. Top the system off, Then run it until it gets up to temperature, Now add coolant to the recovery can so it is 3/4 full. Now shut down and let it cool enough that you can pop the cap. Now top it off again and go for a drive. Check it once it cools down and make sure it is full. You're done.

Reply to
Steve W.

Finally had a clue! Was checking the level/ adding coolant and a nice puddle formed on the ground. Seal around the water pump shaft.

Replaced water pump, so far, so good. Will know in another few hundred miles.

Thanks for thoughts and advice, will advise after a few miles.

Reply to
Miller

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