Low heat from heater

[beretta]

My 96 Z26...

It used to have insane hot air from the heater. my heater core was leaking way back like a couple months after i had the car so this is going back probably a good 6 months now. replace the heater core with a new one. ever since it has not had much heat.

Never really thought much about it until now because the weather is getting colder now. i changed my thermostat last night with a 195. it had a 195 already. put fresh coolant in and still blows the same amount of low heat..

Temp gauge never goes past 1/4 and normally stays at 1/4 all the time. i thought maybe there is a air in the system but i have let the bleeder out near the water pump for like half hour and kept adding coolant and doesnt make any difference, doesnt seem to be air coming out just a constant flow of coolant.

Where does the heater pull cold air from when you change the heat setting to cold ? im wondering if possibly the vent is not closing all the way and its still pulling in some cold air when its on the hottest setting. the higher i turn the fan up the less heat it seems to blow.

Im assuming that there is not an air lock in the coolant system, otherwise i would suspect it would over heat or run warmer then it does, i have never seen the temp gauge go past 1/4 and very seldom do the fans even come on.

Anyone have any suggestions..

[3X00-Modified]

It's very hard to air lock our systems with the way its setup, I've never had it happened and I've had tons of heater core lines off and apart and went back together and only used the bleeder and driving to purge the system.

As far as the core replacement goes, I wonder if you possibly disconnected or messed up the door that moves when you select cold to hot, it's an electronic flapper door.

[beretta]

Im thinking that too.. ... it hasnt had the same amount of heat since i changed the heater core. if i change the setting to cold it goes to cold, and when i go back to hot it just blows warm.

How can i tell if its not closing or opening all the way without taring it all apart... is there a certain spot it pulls cold air from outside i could just block off to test it.

[3X00-Modified]

Well it always pulls air from outside unless your AC is on MAX then it pulls air from the cabin, but changing the temp does not change where the air is coming from, it changes how much is directed at the heater core, which unfortunately is above the core, so there is really no way to check that without taking the core out.

The Beretta air flow goes over the AC condenser core first then is either directed at the vents, if your AC is running, or directed to the heater core to get warm, then to the vents, and obvioulsy unless the defroster is on the air is not cooled by the AC core before going to the heater core, it just passes through.

Here is the system breakdown, the door that opens to direct air over the heater core is #30 I think... It's not labeled on the PN list so I'm not 100% sure on that, but it's controlled by a motor on the passenger side of the assy IIRC... I would check the movement of that to see if its working.



another view

[beretta]

without taring into it too far in the dark... I pulled off the cover on the passenger side lower dash and had a peek in there, all the valves seem to be moving something for every setting although when one of them is pushed full out seems to be moving the cover a little so maybe its disconnected inside.

Also i have the AC pressure switch unpluged since when on defrost setting the AC compressor would kick on and i dont need it coming on in the winter anyways.

so i done a little test, car warmed up about 10 minutes running time 1/4 temp on the gauge. i stuck a digital thermometer with a probe on it into the center heat vent.

On HIGH #4 blower.... 97.7 F
On LOW #2 blower.... 122 F
On LOW #1 blower...... 144 F

Now the 144 on low wouldnt be bad if it pumped that out on high because #1 blower setting just isnt enough to heat up the whole inside of the car, wouldnt be bad if you were sitting inside the duct work LOL.


It used to pump out enough heat to sweat you out of it on low before i changed the heater core, ever since that very day its never been the same i always figured it had some sort of air lock in the coolant system and would eventually work its way out. i dont think thats the reason though.

I remember i helped my friend a couple years ago change a heater core in his 97 grand am, exact same setup as the beretta, same heater box. and come to think of it i dont think his blew really hot air after words either.. maybe from all the tugging and pulling to get the covers off knocked someone off on one of the levers inside.

Ill get at it tomorrow and pull the heater box apart and have a look about. In the mean time if anyone has a digital thermometer they could compare some temperatures that could be help full.

I hate being cold i like my heat hot i want to be sweated out with the heater on low. something is not right.....

[SuzukiGhostRider]

I would tend to agree with Jon on this one. Your blend door is likely jammed open or not functioning correctly.

[beretta]

yeah, i think something is disconnected inside, will find out tomorrow. ac worked fine though, heater settings all work hot to cold floor to defrost. just doesnt get very hot on high

[beretta]

WOW omg.... is there an easy way to put the defrost and rear heat panel back on without cursing the Shet out of it till it goes back into place. GRRRRRRRRRRR.. frustrating lol.

so i tore into it a little today, tryed to pull the bottom off the heater box until i remembered why i broke it the last time, the 2 10mm bolts that go in from the outside by the heater lines, its wet and snowy and cold im not into crawling under it today.

So i was able to pull it down enough to squeeze my hand in there and the heater core dam near burned my hand it was that hot. but still has lower heat on high fan. i wasnt able to remove the core to look above it, thats where the other flap is above the core. i was able to look at the end.. on the driver side is the electronic gizmo for the upper flap for cold-hot, on the passenger side is a little arm that sticks out and i can see it rotating when i select cold to hot.. Appears to be moving but if the flap is moving with it i cant tell.

Maybe tomorrow if i feel up to it ill crawl underneath and get those bolts out to remove the lower cover completely, these heater box's are a nightmare, there must be a few tricks other then tugging and pulling and cursing to get that lower cover off LOL. And to put the defrost-rear heater cover back on.

All i want is Lots of heat...

[3X00-Modified]

There are not two screws outside the car you need to remove...

Read this, It has all the screws necessary you need to remove.
http://beretta.net/forum/viewtopic.php?f=3&t=3873

That also shows the two flapper doors, the larger one is the input the smaller one is the output to the vents.

[beretta]

ok well there is 2 10mm bolts on the outside by the heater lines, i remember i had to remove them before maybe they hold the heater core in or something.

The lower cover is a bugger to get off the way it clips up at the firewall i can never figure it out until i pulled and yanked and tugged and broke something lol.

I managed to split it in half when i changed the heater core and used the soldering gun to weld it back together

Maybe those 2 bolts im thinking of hold something for the AC side..

The bottom cover seems to lock into place at the firewall its a bugger to get out of there. and the worst of putting it back together is the cover the defrost tubes run into then down to the floor for the rear heat i was about ready to just toss it away lol.

I know where the flap is above the heater core i can see the rod come out one side and it does move so either its slipping inside or broke off or just sticking and not closing all the way, i tryed pushing on it while it was turning positions and cant seem to budge it any further and it sounds like something is moving in there.

Maybe the aftermarket core i got just dosent hold the heat as well or flows faster then the OEM ones, the core feels very hot to touch, so im just not understanding why it doesnt blow hotter air.

Im pretty positive before changing it due to the plastic line cracking on the stock one that it used to sweat me out.

[beretta]

i had a think today lol... i changed the thermostat in my car and topped up with coolant for winter a while ago.
I have noticed the coolant level going down a little, not much maybe half a liter when ever i do check it.
Could be just some air in the system.

I have a rough cold start up, always has but when the weather is colder i have to hold the throttle a little and it sputters like its not running on all 6 until it warms up or i rev it up above 2 K it clears up and sounds like its running on all 6 within 15 sec of running or so.

Im wondering..... if possibly the intake gasket has a small leak, like a drip once in a while when its off thats going into a cylinder or 2, that would explain the cold starting issue and the coolant disappearing but it goes down slow, like once a week if i remember to check it and top it up a little.

Is it possible the intake gasket have a slight once in a while drip and no coolant in my oil or oil in the coolant.
There is never any coolant under the car and i never ever notice it leaking anywhere externally, the engine is dry.

I still have very little heat, and i have put a piece of cardboard in front of the rad across the whole thing, there is maybe 4 inches at the top of the rad showing, my temp gauge never goes past 1/4 even on a mild day like today with it being +5 C today. i drove 2 hours today and never never does my temp go past 1/4

I started the car this morning to warm up and brush the snow off and it must have sat and idled for a good 15-20 minutes, when i jumped in the temp was barley off the bottom just starting to move, and not until i drive it for 5 minutes does it hit 1/4.

So i have a cold start issue, takes forever to warm up, low heat, and coolant evaporating (very little) but it does go down.

Any idea's ? i guess i could pull spark plugs and look for bad plugs that could be burning coolant, im afraid of taring the spark plug boots pulling them off since i dont have replacements and it has to be functional. could it be a head gasket ?

I always assumed if the head or intake gaskets were leaking , i would have coolant in the oil, or oil in the coolant, foggy out the tail pipe sweet smelling, or all of the above. and i have neither of those things. and have just done a fresh oil change 500 km ago oil was dirty as heck but no coolant.

[beretta]

anyone ? Mr. 3400 ?

[beretta]

Im starting to think i have a intake gasket problem , engine has 292,000 KM on it now. i have a lower and upper 3400 intake id like to throw on it for the price of the gaskets i think ill look into it. first step ill pull the plugs and see if any of them are burning different.

I filled my coolant tank to the top yesterday and let the car run a while with the bleeder out until the level went down some, will check it in a couple days and see if its still going down.

Here is a video of cold starting.. http://s919.photobucket.com/albums/ad35 ... V03094.mp4

sorry for the sound, its hard to hear it actually miss firing at the beginning my camera kinda distorts the exhaust sound, it doesnt seem that loud lol.

[Money pit Beretta]

It can leak anywhere. Last time mine was leaking out the side where the lower meets the head. I was checking before I repaired it and there was no sign of coolant in the oil.

[beretta]

is it possible i have coolant leaking into my cylinders when the engine is off and sitting ? but see no signs of leaking coolant externally anywhere...

It miss fires alot when you first crank it. im thinking it has coolant in a cylinder or 2 causing it, the scanner shows miss fires on cold start but clears count when it stops. so its no throwing a code because of it. when its colder its worse, when i first got the car it had a little issue but when it was warm out it stayed running and clear up.

Once its started and warmed up, it starts fine all day long. but im pretty sure my coolant level is going down slowly now that i have been keeping an eye on it.

I have a 3400 lower and upper i want to put on if i have to do gaskets. so in the long run if it dont clear the issue up it will be worth doing it anyways LOL.

I should start by pulling spark plugs. ill cold start it and shut it off right away then pull them, look for ones that are soaked in coolant or firing different. that should tell me whats going on.