Howdy,

I have a 93 base pickup with a 22re and have experienced cooling issues in the past that I've been able to fix until now. My upper radiator hose blew last night and I was able to get a replacement and installed it earlier today. I topped off my radiator and made sure my coolant overflow bottle was full, and then drove it to a spot where I could bleed the cooling system using a rad cap overflow funnel. I ran it for a couple minutes until the idle climbed up to 2k rpm and the funnel overflowed with coolant being pushed back out of the radiator. I shut it down, dumped some of the coolant from the funnel back into my jug and started it up again only for the same thing to happen except this time the idle went up to 2k rpm, almost dies, goes back up, almost dies, and on. I left it alone for about 15 minutes not running and then topped off the radiator and drove it home and the temp gauge wasn't alarming at any point during the drive. The heat no longer works at idle, and is super weak while driving with re-circulation on. I left my apartment a couple hours later to go to my girlfriend's, making sure to check my coolant before the drive, it was fine. The temp gauge was fine, but the heat issue persisted. Near the end of my drive, the idle was high, then did the weird up down thing when I parked but the temp gauge was still fine. I shut it down, checked my coolant, fine but the overflow bottle was super full.

I had this weird idle issue only during my active radiator leak a year ago, but replacing it quickly followed by burping it with the funnel immediately afterward worked perfectly fine last time.

Is there just a LOT of air in my cooling system or is it potentially a sign of something more serious like a head gasket? Could it be my heater core or thermostat? Am I still okay to drive the truck for now? Has anyone else here had this kind of issue?

I'm a novice mechanic so I don't know what the diagnostic procedure is for this type of issue or if I'm overreacting. Any help is greatly appreciated!

 

When the radiator hose blew did you drive it far before noticing or before you were able to safely stop?

Do you know what caused the hose to blow? Was it it really bad shape to begin with or did it blow off due to overpressurization?

The 22RE cooling system is pretty easy to burp in my experience, especially with one of those spill-free funnels. Did you have the heater temperature control set to full hot while you were burping the system?

I'm not sure how your later year 22RE controls the cold start idle, the early ones bump the idle up when the coolant temperature is low. If there is no coolant at the Auxiliary Air Valve or Idle Control Valve it could be mistaking the coolant temperature as low and bumping the idle up. But once again, the 22RE isn't usually too hard to burp.

Most auto parts stores loan cooling system pressure testers. You might consider borrowing one of those to see if the cooling system will hold pressure. If it looses pressure, be sure to find where it's going. If it's the head gasket, you'll have sent coolant into the oil or into the combustion chamber and it'll need to be removed before starting.

What city are you located in. If you're close I'd be willing to lend a hand.

 

I noticed when the truck started idling like there was air in the cooling system, the temp gauge was fine so I drove it the extra few blocks carefully to my apartment before popping the hood, noticing the hose, and adding coolant. Also, this happened after I was on the freeway for about 1 hour and 30 mins, but during the drive, nothing appeared out of line (I watch my gauges like a hawk).

I had no issues burping it the last and only other time I had to, after my radiator. I did have the heat and fan all the way on during the process. I also tried again today. I did it for about 30 minutes total but once it got to temperature, I revved it, it sucked the coolant down and I added more to the funnel, it took it, and then stopped taking coolant and producing bubbles after a couple minutes of periodic revving and resumed normal idle so I assumed I successfully burped it until i let it sit at idle at temp again for another couple minutes with the funnel on, when it began regurgitating coolant and doing the up-down idle again like there was air reintroduced in the system.

I also opened the thermostat housing to get a better look at the level of coolant in the engine itself. It was full, I removed the thermostat and noticed it did not smell like coolant, but almost like exhaust or fuel (I have some excess fuel in my exhaust due to misfire, could exhaust be getting into my cooling system? There's no smoke coming out of exhaust as of now). I added coolant to the radiator and watched it overflow out of the thermo housing and did not notice bubbles or anything at all. Thermo was fine and not leaking, but I replaced it and the gasket anyway to be safe. Once I installed the thermo and topped off the radiator, I started it back up, same funky idle.

It would almost appear as though as I am removing air from the system, more air is replacing it. I am pretty sure now that it might be a head gasket, but as a last check, I will definitely try a pressure test, thank you for recommending. How do I know if it has sent coolant into the oil/cylinders after the pressure test? Would I drain the oil or look at dipstick to check it or look into the spark plug hole with a snake cam or something? My dipstick shows my pretty dirty oil still at proper capacity and there is not any of that creamy stuff in my oil cap currently.

I appreciate the offer, but I'm in Eastern Washington. I work at a toyota dealership as a lubetech and there are master techs there I could pester, but I haven't been able to reach them much as we're all pretty busy lately, so I'm trying to do as much diagnosis as I can with my existing resources for the time being.

 

A blown head gasket does seem like a likely diagnosis. A leak from the combustion chamber into the cooling system would pressurize the cooling system and introduce air into it. It would also push the coolant into the overflow reservoir. The pressure may have also blown the hose off making things worse. But some pressure is normal so maybe the hose blew off and then caused the engine to overheat and kill the head gasket. Kind of a chicken or the egg sort of thing.

If you do the pressure test and it doesn't hold pressure, you'll want to know where the coolant is going. A few drops into the oil isn't really terrible but a significant amount (enough to see the level rise on the dipstick) is bad. An oil change will remove any coolant that went in. Water and oil don't mix and water is heavier than oil so it should drain out first as soon as you remove the drain plug. It takes far less coolant in the combustion chamber to cause problems. Liquids don't compress (they technically do but not an appreciable amount in this case) so it's possible to hydraulically lock the engine if enough coolant gets in. Sometimes this bends rods. Best bet is to remove the spark plugs and crank it over a few revolutions. If there is any coolant in there, this will evacuate it from the combustion chamber in a spectacular water show almost like the fountains at the Bellagio.

If you're in Washington state, that's about the opposite end of the country from me.

When burping the cooling system, it's actually faster with the heater control at full hot, and the fan off. This allows coolant to flow through the heater, but doesn't remove heat from the coolant. This allows the engine to heat up faster. It might be useful to put the fan on the slowest speed so you can reach through the window and feel for heat out of the vents.

 

Not to be nit-picky, but the thing is that fluids may or may not be compressible. LIQUIDS are not. Air is a fluid. Water is a fluid. Plasma, while unique, is a fluid. See the difference?

Sorry. Just one of my little quirks.
Pat☺

 

Thanks for the correction. I mixed up "fluids" and "liquids". I've edited my post. Liquids do compress, but like I said, a very small and in most cases insignificant amount.

 

I just got back after spending a week out of town, sorry for the late reply.

The day before I left, I noticed a pretty good amount of white smoke in the exhaust. I drove from my apartment to my mom's home to drop it off before our trip, and ended up pulling over at one point to see why smoke was coming out of my grille and hood crevices, I think I might have an external leak as well as internal. I pulled my dipstick, normal level except there is literally green coolant on the inside of the oil cap which almost definitely confirms my fears. There's also that creamy mayo stuff caked in there which was never an issue before.

Luckily I traveled by air and didn't have to drive anywhere lol. Now I'm gonna do a half oil change and pull the spark plugs to turn over like you said, then get it to a shop me and some friends rent. I put off my misfire valve issues, leaks, and broken stuff for so long I guess this is a good kick in the ass to just replace the damn engine, it has enough issues that I don't have the technical ability to tackle myself. It needs some work that would require the engine or trans be pulled for anyway so I'll just get a beater and project the old girl until she's well again with a new 22re and etceteras.

Thank you so much for your advice and suggestions I really do appreciate it a lot!