Overheating After Head Gasket Replacement

[Nate97limited]

My 4Runner had some leaky valve cover gaskets when I bought it, and I am really unsure how well the previous owners maintained the vehicle. I had had a P0420 code being thrown for a little while prior to changing out those gaskets (not really sure if this is even related). 6 months or so later my rig started to blow steam out of the tail pipe and I had a small amount of milky residue under the oil fill cap, so I decided to replace the head gaskets. I ended up replacing both head gaskets, intake gaskets, exhaust manifold gaskets, valve cover gaskets, thermostat (jiggle valve at 6 o'clock and verified that it is opening and closing correctly), timing belt, catalytic converter, and muffler. I made sure that the water pump still appeared operational, although I did not replace it. The OEM catalytic converter was replaced by the previous owner with a really cheap aftermarket one, and I'm pretty sure that the antifreeze coming through the exhaust burned right through it, so I decided to replace it with a direct bolt on. The gaskets were part of a set (Evergreen brand I believe).

My rig does not seem to overheat at idle (I have let it sit for up to 20 minutes at curb idle), but only seems to get hot when I drive it. The heater will bleed out some of the heat, but if I drive for too long even it does not seem to be able to keep up. When I feel the top radiator hose it is hot and firm at operating temperature (much hotter when the rig is over that), and the bottom radiator hose is cool and does not appear to be squishy. I also do not appear to be boiling over into the expansion/overflow tank.

The 4Runner runs smoother than when I bought it, however with the overheating I am almost at my wits end. Several times I have flushed and filled the radiator (green coolant and distilled water), burped it on a good incline with a funnel fitted into the fill neck of the radiator (made sure it stayed at least half full so that it was higher than any other portion of the engine). I have replaced the one leaky coolant hose that I could find, and I do not appear to be loosing any more coolant. The fan clutch appeared to be seized, so I popped it out and refilled it with silicone oil. The fan clutch appears to be working now. Using the Torque app, the OBD II is showing temps climbing over 220. I am about to take it over to the mechanic to have them take a look at it.

 

[the great him]

im gonna guess you have the right side head gasket on the left side and vice versa... its a easy mistake and they look almost identical, but there are i believe two water jackets/passages that get closed/blocked off by doing this. if this is your issue the only fix is to do it all over again

 

[Nate97limited]

Waiting on the mechanic to do pressure and flow tests, man I am hoping that I do not have to do that job all over again!

 

[LittleCaesar]

The two times I have had autos overheating while running but not idling is when they both had a bad water pump. On one the impeller was rusted away as well as the radiator was clogged. The other time the water pump had gone bad since the tensioner had seized up. Both were serpentine belt driven engines.

 

[Nate97limited]

I am almost hoping that it is a clogged radiator or a bad water pump. I hadn't replaced either, and I guess they could have been broken/ clogged somehow in my rebuild.

One thing I forgot to mention: The heater works really well, I am almost scared at this point to try the A/C until the problem is located.

 

[nissanh]

How old is the radiator? and is it factory? Use a syringe and remove the coolant in the top tank. Then inspect the core. Check for clogged ports.

 

[Nate97limited]

So my trip to the mechanic finished on Friday with a new radiator (the one I had was the original, or at least appeared to be the original, and was really clogged as well as many, many bent fins), new radiator hoses, and surprise surprise, I still had something blocking the flow of coolant.They also said that something was forcing exhaust gasses into the coolant system (although I did not see this). They recommended sending my rig to an engine specialty shop, but after getting their bill I said I would rather check things out myself. After getting it towed home, I broke the engine down again and found out that I had indeed put the head gaskets on backwards.

So after another set of head gaskets (by the way, the Evergreen ones I had used the first time were NOT marked), 2 new thermostats (the O'Reilly one was bad out of the box, new one is rated to open at 160), a new radiator and hoses, double checking the heads to make sure the short overheating periods did not warp or crack them, putting everything back together, coolant flush and fill, topping off my ATF, rebuilt the Aisin fan clutch (original silicone oil was gelled and looked like most of it was gone anyway), and an oil change, my 4Runner is finally back running. I drove around for about an hour today after all of this with the A/C cranked and so far so good. Temp gauge below halfway mark and Torque app shows my temp (at operating temp)is not going above 170 (actually looks like it was right around 165) in 101 degree weather. Now if I had just taken my time to do it right and triple check the head gaskets the first time....:roadkill:

 

[KainDrag]

So my trip to the mechanic finished on Friday with a new radiator (the one I had was the original, or at least appeared to be the original, and was really clogged as well as many, many bent fins), new radiator hoses, and surprise surprise, I still had something blocking the flow of coolant.They also said that something was forcing exhaust gasses into the coolant system (although I did not see this). They recommended sending my rig to an engine specialty shop, but after getting their bill I said I would rather check things out myself. After getting it towed home, I broke the engine down again and found out that I had indeed put the head gaskets on backwards.

So after another set of head gaskets (by the way, the Evergreen ones I had used the first time were NOT marked), 2 new thermostats (the O'Reilly one was bad out of the box, new one is rated to open at 160), a new radiator and hoses, double checking the heads to make sure the short overheating periods did not warp or crack them, putting everything back together, coolant flush and fill, topping off my ATF, rebuilt the Aisin fan clutch (original silicone oil was gelled and looked like most of it was gone anyway), and an oil change, my 4Runner is finally back running. I drove around for about an hour today after all of this with the A/C cranked and so far so good. Temp gauge below halfway mark and Torque app shows my temp (at operating temp)is not going above 170 (actually looks like it was right around 165) in 101 degree weather. Now if I had just taken my time to do it right and triple check the head gaskets the first time....:roadkill:

170 holy crap isnt that super low lol?

 

[Nate97limited]

170 holy crap isnt that super low lol?

Yes it is... stupid me, I took a screen shot of Torque while it was at curb idle (in the shade) and didn't switch back over.:frusty: I started thinking that temp seemed to be a little too low under load, especially in the heat around here! When I actually looked at the data under load it looks to have been around 205. I am still checking it almost daily for this first week, but so far so good.

 

[Jas2171617]

My T4R, the coolant stay about 185 F while driving, ambient is about 100 F around. i think you have the thermostatopen at lower temp than the one orig equiqment, I susgest you use OEM thermostatto see any different.
Good luck to your car.

 

[MandAtaco]

Glad you got it figured out! My buddy did the same thing with his, got the head gaskets on the wrong side and blew the top of the radiator off! Luckily there wasn't any permanent damage!