dwest76

Definitely needs to be bled, when you get an air pocket coming through the radiator you'll see what I mean.

I'm going to get it back from the mechanic tomorrow. His recommendation at this point is to drive it and keep some fluid with me. I didn't realize it, but the other day he drove it and everything was fine (after letting it warm up). So maybe it is air in the system. At any rate, he's telling me not to tear in the motor yet which is what I've been thinking too after all the tests we've done for the HG. I'll keep you posted as to what happens, but I think I will try driving it a little locally to see what happens.

dwest76

Okay, got the truck back on Tuesday and have been driving it for shorter (10 min) trips. Level hadn't been raising to anything out of line so I've been feeling pretty good about it.

So today I decide to drive it close to where I work, kind of a test run. Started it up and when I gave it gas I could hear the air/coolant in the dash, so okay I still have air in it. Sounds like a lot. Drive for 10 minutes and still haven't gotten any warm air out of the front or rear and it's 50 degrees out. So I check under the hood and the coolant has already spewed once and is at the top of the overflow. . get it home and decide to drain some oil. As you can see from the pic, it's a dark brown color. Definitely not milk shake but not black. The pic makes it look a bit worse I think. Then I take the valve cover off. oil in there looks to be the same color. First question is, does that look normal? Oil has about 1000 miles on it maybe, it's syn with a little Lucas thrown in there. The oil was very clear initially and with all the tests I've done I still have problems believing it's the HG. The oil I added back in was close to the same color. I did find one heater hose that I could see was a little loose as it was leaking a little. Doubt it was causing all of this, but it was leaking slightly.

After putting everything back together and adding back some oil, I'm still a little pissed and decide I'm going for a drive to see if it happens again. I drove for about 45 minutes on a hilly road at a steady 55 miles per hour. Absolutely no issues at all. the heat was working again, coolant level didn't rise. wtf is going on??

Cliff Notes: truck acts fine for a few days, then wants to spew again, then is perfectly fine 30 minutes later. Have run every test known to man for HG and all have shown it's fine.

iamsuperbleeder

my friend, your head gasket is definately leaking... that, or your timing chain has worn a hole into the water pump housing (hit the search button on that; that's common too)


plain and simple, that oil is NOT normal... that has some coolant in it...

dwest76

the area around the timing chain looks good...........

wouldn't the leak down test have shown the HG? for that matter the sniff test should have. why would the truck be fine one time and not the next?

iamsuperbleeder

cycles of hot and cold can open and close small areas as mentioned before; maybe it's only doing it around a particular temp? a temp between cold, and full operating temp?

dwest76

alright, on to the HG replacement! what the hell, it can't be as bad as the heater core replacement can it?

iamsuperbleeder

lol, I'd honestly rather do a HG than a heater core again...

dwest76

Well, I finally got the HG done!! Had some trouble getting it started again, but that was because I didn't put the motor at TDC when I pulled the Dist.

Ok, so I was going to let it run for a bit so that I could change the oil and stuff and about 10 minutes into it I started seeing oil in the radiator. After ting my pants and about throwing my work light through the wall, I killed it and drained the radiator again. Put new coolant back in and started it up. Still some small oil spots but not bad. When I had the head off there was some drainage on to the block and everywhere else, so I hope that's what I'm seeing.

Changed the oil, it looked kinda crappy still, but there was a lot of gunk in there to clean out. So I plan on taking it on a road test for about 20-30 minutes and changing the oil and coolant again, and then adjusting the valves/timing. (if we don't get all the snow that is being predicted).

So, my question in the meantime is does the small bit of oil in the radiator raise flags right now? At this point I'm not too worried because of the drainage when I was getting the head off of there, I'm just wondering if anybody has had a similar experience.

TNRabbit

I know how frustrating this can be~

I have another guess; do you have the oil or transmission cooler that runs through the radiator? If you do, I'd check if it has a leak internally between the oil/tranny/coolant passages....

dwest76

I don't think it's leaking in, I think it's residual from taking the head off. Took it on a road test this evening and everything went great! Oil looks good, coolant could stand changing again but looks good. I'm growing optimistic that the HG was my problem this whole time.

CappyKD

Good luck. Hope you got it.

dwest76

Alright, a week and 100 miles later everything looks great! Now it's to start looking at more height. If only I could find a thread on lifting an IFS..........

MyBlueToy

How is you 4Runner running? Same thing is going on with my 86 4Runner. I am at the point where I bring to a garage for some testing. It sucks because I live in Michigan and have no heat and it is cold. Should I have the test done or just replace the HG first?

dwest76

It's running great now, I guess it was the hg all along, it just didn't show the usual symptoms until it got a little worse.

Is yours overflowing out of the reservoir? No heat could mean that your heater core is blocked. I started noticing intermittent hot air blowing but ignored it since the heat had always been questionable in the dash. Then it started being intermittent in the rear heat. Oil was good, coolant was good, compression test was good so I replaced the heater core. then it had heat, but was still overflowing.

Hindsight being 20/20, I should have replaced the HG right away. what else could pressurize the system so much that the overflow spewed every time? My problem was that the motor passed all of the usual HG tests so I kept hunting for this mysterious air bubble. I ended up taking it the mechanic for a leak-down test which also came up as OK.

I would let the mechanic do some tests before tearing into it, but I would be researching how to change the gasket, especially if you're seeing the same symptoms that I was. If you're not, post up what's going on with it.

MyBlueToy

Yes mine is overflowing through the reservoir, at first I had intermittent hot air blowing. Everything that was going on with yours is going on with mine, so I took the t-stat out so it would stop overflowing and now have no heat, most likely because of no t-stat. I drive it only a few miles a day, 5 minutes, so no real time to heat up. I have an appointment on Monday. I will post what the results are. Thanks for a great thread, really nice to know the mystery maybe solved.

MyBlueToy

Sorry it took a while to get back here. It is confirmed, a bad head gasket. Thought about having the head gasket replaced by the garage until I saw the quote. More than I can afford, so I am going to do it myself. I have everything set up with a shop to machine the head and replace the valve seals, supply all gaskets (head set). I look forward to learning how to do this. On a scale of 1 to 10 with 1 being the easiest and 10 being the hardest, where would you guys rate replacing a HG? Also are there any good threads that explain how to do this step by step?

Nogarage

There's lots of info on Yotatech for replacing the HG, if you have a garage to work in you're WAY ahead of the game!...

Best wishes,
Nogarage