Hello guys

I'm at my wits end with this car, I haven't owned it a month and driven it more than 2 days straight without bad news so here's the latest issue maybe you guys have some insight. Side note only bought it because I needed a more dependable ride than a 33 year old Datsun 280ZX that's on it's last leg.

But anyway took the car to a honda mechanic he said the reason the coolant fan didn't come on was the fan temperature switch was bad so I got him to replace that and put a thermostat on it too. Upon doing that the temperature switch was actually broken and the thermostat hadn't been replaced in years. Ok said and done start the car up to see if the fan kicks in and that's when I see why it had been rigged by the previous owner to straight wire the AC fan to a switch running through fuse box. The car runs and runs and it's running cool, then we see water being pushed back through the coolant tank, so he says it must have air trapped so he bleeds the system a few times and it still does it seeing bubbles and foam the fan didn't kick on until about the half way mark on the temp gauge and it the coolant fan finally kicks on. He says that's not normal at all it should have kicked in early. So then he says it looks like I have a BHG (blown head gasket). He used that combustion leak tester " with the blue dye... It started off Blue and if it turned yellow well you know that answer. My car never turned yellow but it went from dark blue to light blue... So am I screwed here cause I'm tired guys I got shafted and looking like it's getting worse and still no reliable car but my dad doesn't seem to think that's the issue in his 40 + years of experience... Any ideas ???

 

I know you have other threads about the car that I have read and might have posted in.

For the stupid slow people - ME - let do one thread about one issue at a time. List everything as they might be related but focus on one main topic/issue.

Overheating.

No "slow" cranks after sitting overnight, right?

When it gets to "temp" BOTH cooling fans cycle?

Ok, so the fans don't come on until the gauge is at 1/2 - not too bad IMO......normally I like to see it around the 4 o'clock position. Does the gauge ever get to 3/4 or "full" hot position?

For giggles, have the rad cap tested - check for any tears in the upper and lower seals of the cap - yes the cap has two sealing points. A tear in the lower or a weak spring sealing the lower will let the pressure bleed off into the overflow and also raise the coolant temp since pressure is not being held in the system......remember science class where "water" boils at a higher temp under pressure.

Then just me here. IMO once one of these over heats the temp sending unit "seems" to get out of wack a bit - again another good tech term. Can you get your hands on an IFR temp reader? I see them on sale at places like harbor freight for ~$25 or some meters have a probe that will read temps. Ok the meters that read temp cost more so the IFR might be a better option.

Read the temp on the head where the temp sending unit is....what is it when the fans cycle? Read the temp on the t-stat housing (where the lower hose connects)....what is it when the fans cycle?

 

actually I only have started 1 other thread on here about the car, and one post in the new members area that's the one you posted comments in. the other post concerning issues of the car, thanks to the guys who posted put me in the right direction and got the major issue of the car stalling and the fan issue situated...


this post was in concern of what this "mechanic" did and had to say and I was asking you guys if any of what he said making any sense in that the car has a blown head gasket that's a new problem that he says the car has and I was asking if anyone has any ideas... but I guess I should have added that to the older post I take it? if so I apologize

 

and to answer your question now that the fan temperature switch and thermostat was installed... the coolant fan finally comes on but it comes on when the temp gauge reaches the half way mark or higher..and the mechanic says its coming on too late its supposed to be earlier and he used that combustion leak tester with the dye and it didn't turn yellow it turned light blue he says I have a blown head gasket.. this is what I'm confused about.

 

I don't know what color exhaust gases will turn that dye.

If an aftermarket thermostat was used, you may want to have one from the Honda dealership installed.

Do both fans now turn on when the coolant temperature rises?

 

Sorry, please don't take my comment the wrong way.

I wasn't really keeping up with the other thread as there was plenty of help being give - BTW nice that you have solved that issue .

Back to the new one. As PA stated, sometimes the aftermarket stats can be a "bit off".

Also there are two switches for the cooling fans (A & B). They are used for different things and have two different temp settings in which they "close". If the replacement switch you got was Thermo B then the setting is too high....like ~225 vs ~195. On the brass base, on the hex part of the switch there is usually a marking of the temp setting. Might want to look at that to be sure you got the right switch from the parts store.

And another follow up to one of PA's questions - do BOTH fans come on when the car/enigne is running? If only one is coming on - you don't want to hear this but......there is another problem that needs to be solved.

 

Both fans don't work automatically the AC fan is hot wired to the fuse box to run when the ignition is on and the coolant fan will now turn on when the temp gauge goes to half way or above but not before that, I was told the head gasket was blown because it's pushing air bubbles back through the radiator and coolant

 

Both fans don't work automatically. The AC fan is hot wired to the fuse box to run when the ignition is on. The coolant fan will now turn on when the temp gauge goes to half way or above, but not before that. I was told the head gasket was blown, because it's pushing air bubbles back through the radiator and coolant.

Help us out with some punctuation. It makes reading posts so much easier.

I would try to get the wiring to the a/c fan back to the stock setup.

It sounds like you may have a leaking head gasket. Bubbles coming out of the radiator and the combustion tester showing positive.

I would try one more test on the cooing system.

Rent a radiator pressure tester. Pressure up the system to about 15 psi and see if it holds pressure. If not, try to locate a coolant leak. If you pull spark plugs and see coolant in the cylinder, then that pretty much verifies a bad HG.

 

Sorry for the missing punctuation, typing this from a smartphone while on breaks at work so I have a time crunch.

But the wiring is what I'm tackling now because the previous owner jacked it up installing what seems to be some type of device for hands free calls or alarm. I can describe it as a small antenna located right above the rear view mirror attached to the windshield (on the inside of course) and it has a phone symbol on it and I traced the wire around and under the carpet to the rear speakers it seems. And also they installed a crappy Jensen radio. I got the nightmare car

As for the radiator pressure tester, my dad says he had one in his tool shed I can use, I swear I can't afford any more bad news about this car

 

I am 90% sure you've got a blown hg. I had it pushing steam/air to the overflow, replaced the whole cooling system and still ended up having to do the hg. The blue liquid test is a waste based on my dealings with it. That crap stayed blue on mine but it still was pushing exhaust into the cooling system thru the hg.

Sorry I know not the best news, I know everyone is diaging the fans but with you having 1 that kicks on at the right time (1/2 gauge) that's not your biggest problem.