1990 Accord EX Heat Problems

[zachattackzero]

I have a 90 Accord EX (2 dr/ 5 speed) and when I go on longer road trips, or about 50 miles or more I should say, after I get off the highway a lot of times my heat gauge will start to rise steadily while it's in neutral and/or when I'm at a stop light. If I rev my engine higher it will go back down though.

 

I'm trying to decide if it's the water pump (i.e. pain in the ass) or if it might be thermostat (i.e. piece of cake). I just don't have the tools and time at this point to just try the thermostat replacement seeing as how I'm at school right now.

 

I just want to get it taken care of sometime in the near future, seeing as how the weather is steadily getting warmer (hopefully it stays that way...but then again I'm in Iowa where the weather changes from snowing one day to being in the 70's the next...).

 

What do you guys think?

[James Matteu]

My first Honda (1987 Honda CRX DX) gave me so many overheating problems, and I put in so many wrench hours trying to do as little as possible to remidy the problem since I "didn't have the tools or the time" either; that when I got the 1986 Honda Accord and the temp indicator rose ever so slightly, I ripped appart the cooling system down to the water pump to visually inspect everything.

 

I learned from the CRX, that not taking the time to do it right the first time would cost me more time and money down the road.

 

My opinion: buy a water pump gasket (Honda P/N 19222-PT0-300), buy a thermostat (Honda P/N 19301-P08-316 -Nippon), buy 2 gallons of Honda Coolant, and then take the time to visually inspect the waterpump, change the thermostat, and change your coolant, and while you have the water pump off, you can change the gasket. If you end up having to change the water pump, the new unit will come with a gasket, so you will have an extra (a small price to pay for playing it safe).

 

Gasket should only be a few bucks anyways.

[Turtlehead]

As James said, it could be the thermostat.

 

I have a couple of questions though:

 

1. Is the fan coming on when it is over heating? If not find the problem with the fan.

2. Is your coolant resovior completely full? If so remove coolant down to the max level. Top off the radiator if it is low and drive the car. Does the coolant resivior fill back up to the top. If so, probably a bad head gasket leaking exhaust into the system, causing air pockets (steam) which when it cycles through the system can cause the engine temperature sensor to read hotter then normal temps.

 

My guess without looking at the car is it is either a fan issue or the thermostat. But checking for a bad head gasket is not a bad idea.

 

Check the weep hole on the waterpump located on the firewall side of the engine, about half way down the T-belt cover. If there is coolant residue in the weep hole then the waterpump if failing. If that is the case then you are due for a T-belt/water pump service, and while they are doing that they can replace the thermostat (since the coolant will be out of the system anyway (makes for a cleaner job). While doing all that, if you upper and lower radiator hoses are original, replace both of them NOW. It should not be the water pump causing the problem, unless it is a GMB piece of aftermarket crap.

[James Matteu]

1. Is the fan coming on when it is over heating? If not find the problem with the fan.

Long ago, I fixed my girlfriends 1993 Acura Integra's overheating problem.

 

I remember the cooling fan stopped working and I erroneously focused on getting it to work (changed the motor, sensors, relays, etc.).

 

It turned our the fan was an indication the water pump had been failing for some time. The water pump "moves" warm-er water past the sensor that switches on the radiator fan. Once the pump failed to move warmer water past the sensor, the radiator fan stopped working consistently, despite the rise in coolant temperature.

 

Once the water pump was visually inspected, I discovered that most of the blades on the pump were missing.

 

Just thought I would share.

[Turtlehead]

That is true, but if the fan cycles on, and stays on for a normal cycle (does not stay on constently), then it should be pumping coolant. If is stays on for a long duration (say longer then 10 seconds) then yes there may me a constriction in the cooling system. Debris from someone who dumped head sealant in the system, a thermostat stuck partially open or closed, etc. It is worth looking at or thinking about the pump, but if it is a Honda pump (or at least the drive belts are Honda so you would hope the rest of the components are too) then that is one of the last things in the order of what to look at that we would look at. Diagnosing the fan is simple, if the car is over heating, the A/C is not on, and the radiator fan is not working, then that must get fixed first. If that solves the problem then done. If the fan works, then the thermostat is the next logical step given the age of the vehicle (considering they are ususally good for about 10 years). Then from there, temperature sensors, water pump, other constrictions in the cooling system, head gasket, etc.

 

I have had heads off cars that people had put head gasket sealant in, and I will tell you what, between all the constrictions in the holes on the head gasket, and the fact that you run the rick of clogging the heater core for the car, I don't know why people bother with the stuff. I don't know how coolant was efficiently circulating in one of the cars. Either fix the car right, drive it until it totally goes, or sell it as is. Sorry, that was a bit of a tangent.

 

Cheers.