my b16 is running between 230-250F, but its not losing any coolant, but it is bubbling back into the overflow bottle, im not burning any oil either, all the sensors are new, and the fan works, IS IT A HEAD GASKET PROBLEM???????

 

Does it run hot only at low speed or at highway speed too? A compression test would be a good idea. A simple test is to start it from cold with the rad cap off and look for bubbles right away in the rad, not the overflow. Bubbles in the overflow may just be from being so hot.

What radiator are you using? The little half width one in Civics may not be enough for the B16 down south where you are.

Is the thermostat OK, water pump, blockage in the system?

 

Put a Honda thermostat in, Bubba.

 

its a stock b16 del sol, it has the stock rad for the dohc, its new by the way, all the sensors are from honda, i'll check that bubble theory at cool down time, and it runs at around 210f, but once it warms up from high speed driving, it reads around 230-250F, but really only after high speed driving, and it wont cool down to the stock 210F. but if i drive slowly, the temps wont hit that high umless i push it.

 

If a new thermostat don't work. Just run without 1.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bubbajim &raquo;</TD></TR><TR><TD CLASS="quote">its a stock b16 del sol, it has the stock rad for the dohc, its new by the way, all the sensors are from honda, i'll check that bubble theory at cool down time, and it runs at around 210f, but once it warms up from high speed driving, it reads around 230-250F, but really only after high speed driving, and it wont cool down to the stock 210F. but if i drive slowly, the temps wont hit that high umless i push it.</TD></TR></TABLE>

one question. how do you the temp that coolant is reaching? and, a 210F is still to hot. it should between 180 - 195F. However, it maybe a blown gh.

 

wouldn't a blown hg results in coolant leaks? He said he doesn't have any coolant leaks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by david90 &raquo;</TD></TR><TR><TD CLASS="quote">wouldn't a blown hg results in coolant leaks? He said he doesn't have any coolant leaks</TD></TR></TABLE>

yes. but however, it only be an internal leak rather than a external leakage.

 

ive done the cool start up while checking for little bubbles, and there was none, im convinced its a small leak within the head gasket. so i decided on parking the car until i take the head off, it might end up being a can of worms!

 

Did this problem happen after putting in a new thermostat ? If its using water then you have a blwn HG but you would also have steam coming from exhaust . I do know Hondas a very hard to purge all the air from the system so make sure all air is purged and make sure your lower radiator hose is getting good and warm if the top hose gets hotter than hell and the lower one just is warm then change the thermostat out for another one . The last time I changed mine the new one was bad it wouldnt open up all the way causeing my expansion take to boil over . Oh and dont try to look and the water in the radiator with the cap off , once the thermo open the water flows sraight up and will blow right out .

 

ill try one more thermostat, after that, the heads coming off.

 

Could also be a bad water pump. I have heard of some with the pump impeller loose on the shaft so it just spins. That would make poor water flow and give the symptoms you are seeing. How old is the timing belt? If it's been on a while, maybe consider replacing the belt and pump.

 

but wouldnt the water pump squeel? i just bought the car with 156,000km, so im guessing they changed it at 100,000km. or are you saying that its totally loosened where i wouldnt be seeing the effects of a water pump gone bad? what other sign of water pump damage should i see if the blades of the pump are worn off?

 

i would definatly makle sure the cooling system is bubble free, bleed it and let it idle with the radiator cap off.

 

Basically poor water flow in the system. When the impeller spins on the shaft, there is no noise because it's inside the motor and surrounded by water. What happens is that there is enough friction between the parts to spin OK at low speed, but at higher revs and load, they slip. This would not cause a leak or any external obvious problem. Your description sounds like poor flow. That makes me think blockage somewhere in the system or a bad pump. Also possible there is air in the system. Did you make sure to bleed all the air out at the bleeder valve?

Many people replace the water pump and timing belt at the same time. If an aftermarket replacement instead of Honda, who know how good it may be? Or could be the original and just worn out. A compression test would show any head gasket leakage if that is the cause. If a bad gasket is the overheating cause, it is leaking combustion gasses into the cooling system. That type of leak will show on the compression test.

 

Can I bud in here and ask a question? Someone I know is having the same problem with a toyota, and he just put in a new radiator and is running without thermostat. What would the bubbles tell you the problem is? How can you tell if the water pump is bad, is by either leaking or squealing noice? The radiator place asked this guy if the water pump was leaking, he said no so they ruled that out. I have no idea where he took the car.

 

so basically, the timing belt has to come off before the head has to come off, so what i'll do is take one step at a time, water pump and timing belt first(examining water pump), then we'll move on to the head., hopefully it is the water pump, if not, i guess im slapping on some cool **** for the b16.

 

The bubbles are from compression leaking out of the head gasket into the cooling system. A lot of companies save a buck by using a plastic impeller on the water pump or pressing it onto the shaft. The plastic ones get old and brittle and loosen up on the shaft. Metal ones that are pressed on can loosen up over time.

Some motors will overheat without the thermostat. In some cases it is a problem with how the coolant circulates in the motor. An RX7 needs the thermostat or a blockoff plate or the water won't go through the block before heading out to the radiator. I don't know about the Toyota.

When having an overheating problem, check the sensor and guage to be sure it really is overheating and do a compression test to see if a head gasket problem.

Remeber that water pumps can fail by not pumping properly, not just leaking. Leaking just means the seal has failed. A lot of times the weep hole in the pump is really hard to see so it can be hard to detect a leak there if it's small. Consider a cooling system flush. Some previously failed part can leave junk in the cooling system that may block it partially.

 

thanks guys.

 

Thank you for the info as well Mohudsolo

 

I'll add my 2cents with my overheating problem with my truck.

We replaced the water pump, new fan, replaced head gasket. And still over heated at high way speeds.

You know what our problem was? We then replaced the radiator. Perfect, ran like new.

The old radiator was jammed up with "black junk". Don't know what else to call it. But I'd try having the radiator flushed/cleaned first. It could just be clogged.

Goodluck, don't let what happened to me happen to you (coolant plugs in engine blew out, spilled into my transmission, destroyed that and left me stranged on I-4, $1000+ later...replaced radiator)