Hi all,
I have an '86 4runner and it has had a coolant odor in the cab for some time. Mostly when the heat is on. I have already done some research and have determined it to be the heater core. Of course, not being an expert I could be wrong. What else would I look for? And if it is the heater core, is their a temporary yet effective way to deal with the leak without pulling it and repairing or replacing it. I simply have no time to deal with it right now unless I simply have to. Thank you!

 

do you still have heat coming in with the heater on? if not, then it is almost guaranteed to be the the heater core. what you can do as a temporary fix is bypass the heater core. it will fix the leak, but you will not have any heat. on the front side of the heater core, there are two hoses - an inlet and and outlet. the coolant goes from the radiator, into and out of the heater core, and then into the engine block before it returns to the radiator to be cooled. by connecting the heater core inlet and outlet hoses together, you are eliminating it from the cycle.

 

I still have really good heat, and getting better since I put a deposit cleaner through it. Being that it is winter, I would rather not have no heater if I don't have to. Any other options. BTW, thank you for your input. I did read about the bypassing in another thread. Like I said, I'd rather not. BURRRRRRRRR!

 

Well, if it's the heater core you're pretty much in a bypass, replace, learn to love the smell of coolant situation the way I understand it.

If you try something like Alumaseal or Bars leaks, it is likely to plug the small passages in the heater core - stopping the leak, but significantly reducing (or eliminating) the heating and requiring replacement in the future...

4Runners may have TWO heater cores - one for the front, one for the rear seat heat. If it's the rear, you could certainly bypass that. Not sure if they had the rear seat heat in '86 though...

 

Don't use those stop leak products, they screw up alot more stuff than they fix.

You need to either bypass it or fix it, period.
Coolant and its vapor is toxic so I don't recommend driving like that for long.

 

Thanks all! I was afraid this would be the case. There is no heater in the rear. So, that answers that. A friend recommended pulling the h.c. and using J.B. weld to plug the leak. What do you all think? Would it work?

 

Don' waste your time, get a new heater core or you'll be repairing it again soon.

 

Once you go through all the effort of pulling it, you may as well put in a new one.

Heater core for my Impala was $60, so they're not that expensive (well, dealer quoted $210)

 

Okay then. S'what I figured.Thank you for laying it out so simply. LOL! I do hate d#ckin' around only to have to do it again. I have had a lifetime enough for two or three people doing that. So, do you think an aftermarket would be adequate (price $91.99) or would it be best to go O.E.? The aftermarket is more readily available. Not to mention the stealer wants $325. Ouch!!!! Any experienced suggestions? And for those that have done the job, 'bout how long did it take? I've definitely decided to replace. So, any helpful tips as well?

 

OE is almost always best but at $325 (ouch!), I might consider an aftermarket.
You might try one of the online OEM toyota parts places too.

 

Just to be sure, I found that the heater hose to the left going to the firewall leaks a bit. I don't believe logically this would wet the carpet inside or produce the fumes, but would this be the issue? Doesn't hurt to ask!!! Also, the hc for the model 4runners with rear heat (I assume this would be SR5 models, mine is not) seem to be cheaper yet smaller and with shorter inlet and outlet pipes. Would this be adaptable?

 

Well, I'll be! I jus' had someone tell me alot things that lead me to believe it actually could be the hose. Mostly because the heater does work well. BTW, it's the one on the right that leaks. Which I was told was common and can then leak on to the heater core and create the same syptoms. I got to work today and I smelled like I'd been cleaning radiators that morning. I wonder if that would explain the weird tumor looking thing on my head??? So, tonight it's change hoses and clamps and then I'll see if that does the trick. Gawl dern! I hope so! Needless to say I found one in excellent shape on ebay going for $10 at this time. Anyone need a heater core? Wait I still might!!! Ha!

 

hopefully it's just the hose. usually when the heater core kicks the bucket, you have no heat whatsoever and the coolant fumes fog up the inside of the windshield.

 

Yes, thank you! That's not the case here. Just fumes and a damp floorboard. At first, someone told me heater core. So, that's what I believed until further research. Then my wife and I ran across a couple of sites that said what you are saying. And when we asked the person who said it was the core, he says,"Oh, yeah. That could be your problem." Changing hoses is much easier and much cheaper. Whatever it is, must have been leaking for a while. Would explain the rust under the dash and in the floorpan.

 

I had the same problem in my 84 Xtracab. The solder joint on the top hose of the radiator deteriorated with age. I found a replacement radiator locally for $120 - problem solved.

 

Good deal! When I bought my "Rummer" (I jest) 4yrs ago the rad was completely shot and needed a new thermo. Not to mention timing chain, tires, shocks, etc. Aside from the latter, I found a really inexpensive rad out of Memphis for around that. No drain cock, but at the price it works well. I use my rig for utility purposes mainly. I am amazed at the things this little four banger will pull. My friend was rather impressed when it pulled a big Plymouth Trailduster (think Dodge Ram 4x4 SUV) up a muddy incline. Good tires were a factor, but the low gearing was the axiom for sure.

 

thook --

What sites were you visiting when you found this information regarding your coolant leak? I have the same issue with coolant on my floorboard (driver's side) but pressure testing the coolant system there are no signs of a leak.

Did you still have to remove the dash to get to the hoses you are referring to or are they accessable via the engine bay?

Thanks,
James

 

Sorry, I hadn't noticed your reply. I have been rather busy, as usual, and hadn't been back here for a few days. But, quite honestly, I am not sure what sites they were exactly. I didn't keep track. However, the key words I used were "coolant odor in cab or heater", "leaky heater core", etc. Using google you should be able to find and weed through plenty of info. It is the two hoses leading to the firewall via the engine bay right in the middle behind and up from the motor. One has a cable assembly/lever mounted to the firewall it is adjoined to. The other to the left of the latter runs from the firewall down to the side of the motor, driver side. Hard to miss. Note: the leak in my runner is on the passenger side. Nevertheless, I suppose the coolant could leak to just about anywhere considering I have rust spanning both sides of the dash and floorboard. Do you have coolant odor in your heating/air system? Does this help?