microwave

For some reason I have no heat when I come to a stop. So far I have checked the fluid level, replaced the thermostat and flushed the heater core. The heat works great while I am moving.

Does anyone have any idea what might be causing this?

Any help would be greatly appreciated.

gearbox

iTrader: (95)

is the waterpump okay?

ClickRight

My 04 civic does this as well. Anybody have any thoughts?

jackoncruzpr

Check your water pump. Make sure that you dont have the A/C button on.

Thrasher086

I had the exact same problem and it turned out to be the head gasket. Around 500-600 to fix. It is covered under power train so you should be fine if you still have it.

briand17a2

EDIT...i hope my HG's ok. Running a comp test today. Never went above 230F...not boosted, no advance timing, running 92ish octane on the regular... wtf

microwave

You know gearbox I was wondering that. If the impeller wasnt spinning wouldnt the water pump leak?

Im not sure what the deal is. If I rev the engine even alittle the heat will kick out. I also have never had trouble with overheating, there is no coolant in the oil and no the a/c isnt on.

Nameless

iTrader: (20)

If you have a 1.7L, dont put premium gas in your car. Waste of money, bad for the engine. Just stick to regular gas from a reputable gas station and your wallet and your engine will be happier.

briand17a2

^ I agree on the waste of money for premium, in the sense that it is not required to operate the motor. However, this is why I do it anyway...

The factory D17A2 compression ratio is 9.9:1, not exactly a "high-compression performance motor", but not exactly low enough for say, a boosted application, where 8.5-8.8:1 would be more suitable.

The factory motor uses a knock sensor to listen for signs of detonation.

If the ECU finds out from the knock sensor that knock is occuring, the ECU retards ignition advance.

Maximum allowable ignition advance is optimum for torque and power, where "maximum allowable" is whatever the ECU thinks it can get away with without signifigant knocking.

Ok, now the octane rating for US gasoline is basically a measurement of how resistant the fuel is to unexpected ignition; a "guarantee" that the gas can be compressed a certain amount before it self-detonates; an "accuracy" rating.

As the gasoline mixes out there generally contain the same amount of energy, the one that is more "accurate", will allow the ECU to run more advanced timing more of the time.

Lets say 86 octane is used. On average, for the same amount of ignition advance (and compression ratio), 86 octane gas will self-ignite (knock) more times than say, 89 or 92 octane.

Using 86 octane, which will knock more, the ECU will retard timing more often, and less torque and power will be available. If 92 octane is used, the gas will knock less, the ECU will keep timing advanced as much as possible, and more torque and power will be available.

If you had a 11:1 CR, you could get away with 86 octane gas, but you're ignition timing would probably never be "advanced", if not constantly retarded. So even though the engine has a high compression ratio, the power level would come down as timing is retarded to compensate for knock.

Overall, the octane rating places a limit on max power and torque for a specific CR (and a whole bunch of other factors; not germane to this post).

The real question is, does 92 octane make more whp and wtq than 86 on the D17A2? I don't have the dyno sheets to prove it, but it certainly feels more responsive an torquey with 92, provided I reset the ECU when switching octanes.

So basically, I agree that it is more money spent. But as far as a waste of money goes, you could group all other tuning for the D17A2 into the same category, unless you have a P&P head. In that case, the higher VE would make bolt-ons more beneficial, cost/performance wise. 92 isnt required, but neither are exhausts, CAI's, suspension modifications, turbochargers, NOS injection, car stereos, etc...

Sorry for the long post, it just hit a nerve. Lots of people ask me why I tune my car, wasting all that money and time, etc. I do it because I like to turn wrenches. I like trying something and seeing an improvement, etc. Its a hobby, but damnit, I could have a whole lot of much worse hobbies (like weaving through traffic at speed on a CBR1000RR, but thats over with).

Lol, anyways, good times, im off my soapbox now. Hope everything turns out with the cooling issue. Im working on this myself, so if I find anything out, ill post it.

microwave

Well I just drove 60 miles home and the top radiator hose was hot the lower was cold, very cold. I guess that would make it the water pump?

wheelspinLX

If the water pump were bad wouldnt it tend to make the car overheat?

microwave

Sorry for the stupid question but is there a bleeder valve for this car that I am missing?

tuningmycivic

iTrader: (11)

doesn't the lower hose go to the engine and the upper come from? so in essence, coolant coming out of the radiator should be cooler than that coming in?? or am i backwards?

jackoncruzpr

Your water pump impeller may be corroded and worn out. Thats why it only outputs heat when you rev the engine.

After a while the water pumps on these cars wear out. The impeller fins get shorter and shorter. At normal cruising RPM its sufficient for cooling the engine. But at idle it cant move ( pump ) enough water through the system.

microwave

Its still a possiblity. The water pump is only a few years old and has 43k miles on it. I haven't been home for a week or so to check it out. I found a manual online and am going to try to purge the system again to see it there is still air.

briand17a2

microwave, did you recently mess with the torque on any fasteners that thread into the cylinder head? Like exhaust manifold fasteners?

xproductionz

iTrader: (14)

if upper hose is hot and lower is cold thats usually a sign of either water pump and thermostat going out

Bb0iPn0y

how much for a water pump and a thermostat?

briand17a2

waterpump ~$85 from dealer in atl

thermostat ~$40 from dealer here, or $15 from pepboys.

gaskets and whatnot are ~$2/each from dealer.

Go to www.honda.com, search for e-service or online parts or whatever. Honda has the complete parts database online for your car with drawings etc...

Water pump replacement can be an all day thing though...

microwave

Nope.

If it is the water pump I'll wait until it tries to overheat before I replace it. Its in with the timing belt so I really dont want to pay to have it done again so soon.

I ran it again for an hour with the cap at first click trying to bleed any air that may be in there. Both hoses got hot and the heat was even hot at idle. It is more of a hit or miss thing. Thats what makes no sense.

gearbox

iTrader: (95)

to make sure its not air in the heater core which is a common problem with this car, take off the rad cap completely and start the car cold. let it warm up to operating temp (revving lightly will speed this up), then turn the heater to full blast hot with full fan. watch if air bubbles are coming off the radiator. continue adding coolant to keep the level high enough where you can see the bubbles. wait until they clear up. then press the ac button and more air will come out. you may have to switch back to heater again and watch for bubbles. if there are still bubbles after 30mins, theres a good chance you have a slow headgasket leak.

and no if the waterpump is damaged, it shouldnt leak. there is a gasket seal around it.

microwave

If its not overheating would you replace the headgasket away if this is the case? I have done what you said a few times now and I still have bubbles but like I said it hasn;t ever moved off its normal operating temp. Better safe then sorry so I dont warp a head?

pheaton

iTrader: (6)

So strange for it to be a water pump or head gasket after 40k. Thermostat I could understand, but if the Thermostat was seized up you would get little or no heat at all, or the opposite (too much heat all the time).

Is your car still under warranty? If so don't mess with it, take it in.

Lastly, how long have you had the car? Also, honestly, how hard to you beat on it? It could very well be the head gasket at this point.

pheaton

iTrader: (6)

Maybe I'm off, isn't the water pump more of a thing you do with the timing belt?

gearbox

iTrader: (95)

when they did my headgasket, it was a very small leak. enough that on some cold starts, i would get a single cylinder misfire because of the small amount of coolant that leaked onto the spark plug. then it would burn off and drive fine til next time. also there was small patches of dry coolant in the exhaust pipe. so i already knew what the problem was. and no it never overheated, it wont if you have a small leak in the gasket. have a compression check done on the engine and also a coolant system pressure check. that will tell you for sure. dont worry about the head warping, it doesnt happen unless the temp needle goes above normal. water pump happens to run off the timing belt thats the only way theyre related. all water pump does is circulate coolant so the engine doesnt overheat. if its broken or not working well, the coolant may not move enough through the heater core so you will have no heat. but maybe when the car starts moving, it works a bit better.

pheaton

iTrader: (6)

^^ Correct. I just meant to change the water pump with the timing belt just for convenience sake while you had the belt off, because the interval is about the same?

gearbox

iTrader: (95)

oh yeah might as well, the labor is the same anyway so its cheaper to change both together. i also change the crank pulley since it usually goes out around 60k miles (at least the dampener inside breaks down).

microwave

Pheaton, I car has 145k on it and its well cared for.


Gear, heres what I think is happening with the heat. There seems to be a fair amount of exhaust moving through the gasket that is creating big air pockets. Every time I stop moving the air gets trapped in the heater core and I get no heat. The coolant pressure test was normal. I am going to have someone do a compression test.

Thanks for all the help man.

What did you pay for the headgasket job?