end user

Ok I have a 88 Bronco with a 302. The car has sat for 4 years and I got it running in the last week. I'm pretty sure this started before I parked it.

What's happening is I'm losing tons of coolant and its no where to be found. If I drive for say 2 hours on a hot day I'll lose about 2L of coolant.

Here are the tests I've done and all are negative. The truck runs good, no hesitation, bad idle etc...

When idling there's lots of condensation. it tastes like water and no smell of anti freeze in exhaust.

I've used a Lisel combustion test kit in the radiator and negative for exhaust, I triple checked and check that the fluid was still good by putting it by the exhaust. I also used a MityVac pump do draw in any air.

There are no bubbles in the rad that I could see.

The spark plugs look ok for being in the car for 6 years and don't look like they were steam cleaned from say coolant leaking in.

When I drained the oil it looked normal old black. New oil still looks good and no white foam or streaks.

Did a dry compression test and the range from 1-8 was 170-175 all with in max 10 psi.

I tested the rad/cooling system with 13PSI and there was a 2PSI los over 15-20 min. Not sure what that means.

I've looked everywhere and only last thing I can think is using a dye and UV light test. So got lot of dye ready.

Anyways I'm stumped, most are saying not head/gasket but where is all the coolant going to?

Matthew Burr

its being sucked into your engine

means you have a blown gasket and or cracked head/s

end user

Could be but there's not one symptom of a blow head gasket, don't think there's an on engine test for a cracked head.

ATM is contemplating a swap but there's everything I've done

• -No water in oil or dipstick, oil is clear (changed it about a week ago) the old oil was dark/normal no water/bubbles or streaks.
• -Checked rad for any air bubbles when running there were none.
• -Compression tested cooling system it dropped about 3psi in 20 min so a small leak somewhere. Tested rad cap it held pressure.
• -Tasted condensation while idling, tastes like normal water vs sweet then bitter antifreeze.
• -Used a Lisle exhaust leak test on the rad and use a vacuum source and a MityVac to suck in any air and tested showed negative for exhaust gases in coolant.
• -Checked heater core, its fine.
• -Ran bunch of dye in the system and checked all over with a UV light, no leaks anywhere.
• -Compression test was good from 165-175 although leak down test I could hear all cylinders leaking air through drive side valve cover/oil fill hole. So possibly worn rings which would be with 330K on the engine.
• -There is no white smoke out of the back whatsoever, with that much water going (4L per day you'd figure it would show)
• -The truck idles perfect, has lots of power and doesn't overheat, just uses up coolant.
• - The spark plugs were changed last 6 years ago and when I pulled them last week they looked fine and normal color even got second opinions from local mechanics. I've driven the truck for a week before the spark plug change.

At this time I'm stuck and my next thing is to swap engines, found same year 302 locally but man they are rare, didn't think a day would come when a 302 was hard to come by.

Matthew Burr

i worked on a guys truck not too long ago, he told me it over heated but not how badly. he also claimed a mechanic told him this that and the other was wrong with it. then how he had changed the water pump but snapped a bolt off and that it must be leaking because he had to put water in it every week.

truck ran great when driving down the road but it kept wanting to die at the stop signs.

so i started going through all the electronics checking the sensors. absolutely nothing. other mechanic claimed his EGR valve was bad, checked that, it was fine but the engine idled extremely high with the port open to the air.

so after all the frustration i asked him how much water he was adding because i hadnt seen any dripping on the ground. turns out i was missing the white smoke out the back of exhaust.

he had overheated the motor to the point it had seized! the engine was sucking water through the head/gasket, burning it and spitting it out the back. it ran so well down the road and with the egr open because it was equalizing the pressures and fuel/air mix enough for it to fire relatively properly.

so lesson learned, water in exhaust, loss of coolant = bad head/gasket regardless of engine performance

Chris_1

iTrader: (1)

4 litres is a big leak. If it's not showing up in the engine compartment, it's blowing out the exhaust.
I read what you wrote, but it has to be going somewhere. Your oil isn't overfilling, so it's not going there. Only one other place. You need a head gasket would be my guess.
Head gaskets is way cheaper than a new motor.
Could be a head, but those are just E7TE heads, they're cheap enough if that turns out to be an issue.
When I did my head gaskets, I just had the heads rebuilt while I had them off - it was only an extra 200.00 to have them done.

SkipNChurch

I just got done re-popping my head gaskets on my 96 351w due to electrolysis etching away at cylinder 4 as hopefully seen in pic.

Truck ran for years always needing a "touch of coolant a week" to keep her happy.
Loaned my sled out, user didn't do as instructed.. Oh well, learned lesson.

HTH in diagnosis.

kevinL






One can see where slow etching occurred. When engine finally quit, cyl's 4 and 3 were full of coolant.