240SX Heat issues..

[fuzion]

If one of you kind engine smarties could take a look at my post here & let me know your thoughts I would be most greatful... Thanks!!

[NISTECH]

have seen a car come through our dealer with a similar over heat problem. The car had everybody and their mother workin on it before it came to us. what we found[ when we realized it we all got a good laugh over it too] the fan blade had been installed back wards. easy way to tell is while its running rev it up and place your hand at the front of the valve cover. If the air flow doesnt feel as though it blowing against you it is probably on backwards. it could also be your fan clutch thats gone out. when its warmed up shut the car off and try to spin the fan there should be some resistance when turning it. it will spin but it wont free spin if you try to spin it. It will stop almost immediatly upon letting go of it. The other problem is the bleeding of the system as mentioed in the other thread. you need to elevate the front end of the car pretty high while filling it so it will clear the air pockets.

[fuzion]

Fan air flow is correct; but I do notice one thing.. you can hear when the fan is on and it seems like its only on for a few minutes when the car is cool or when it's cold outside.. then I never hear it again..

Does the headgasket situation sound ok to you?

How long is it before the fan should lock up and start cooling? When the thermostat is in within 5-10 minutes the temp gauge is higher than it should be.. should the fan be spinning most of the time?

[NISTECH]

the fan should spin all the time. but doesnt go into lock up till it gets hot and for a short time when first started. as far as the head gasket goes. if you got it for your car it should be right. I havent had a head off of a KA in some time so I dont recall exact locations of the passages from head to block.

[fuzion]

Hey where at in Norcal are you?

Yeah the fan is spinning all the time freely; but the only time its locked is when its cold outside or the engine is cold.. otherwise its never on.. even when the temp reaches 1/2 way up its still not on..

[JJ240]

When you replaced your headgasket did you have the head checked to see if it was true or needed milling?

[NISTECH]

sacramento area, south about 30 miles town called galt.

[fuzion]

ahh... was thinking maybe you worked around the corner from my place @ Turner Nissan in Sac

The fan clutch from Nissan is around $200.. should I get one from Nissan or just get an aftermarket one for like $70?

[NISTECH]

no but use to work there about 5 yrs ago. You can go aftermarket on it as long as it is correct bolt up. the longevity of it might not be as good though. have you tried one of the online dealers listed in the ads to the left? they sell at whole sale prices. a bit cheaper then list you got at the in town dealer. I work out near rancho cordova.

[p00t]

that head gasket looks extremely odd to me... check this out:http://www.240sx.org/links/ins...0.htm

this is from the 240sx.org installs page. Check out the pics of the head and block, its SOHC but the coolant passages are identical (same block). You see all those oval and round holes in the pics of the head? Those are coolant/oil passages... meaning your head gasket should have holes for all of them....

If your absolutely sure that the gasket was missing holes heres what I think you should do:

1: Get a new good gasket.... find out where you got that other gasket and let them know about the problem, this isnt to get you a refund but to maybe prevent this from happening to someone else. Also make sure that the gasket just didnt need to have the coolant holes punched out, (they might just be perforated and you need to punch em out with a screw driver).

2: Take the head to a machine shop and have them resurface it.... and you can just pray that the block is fine..... Problem I'm seeing is you were only cooling maybe half the head and block and the other side was getting pretty hot... possibly warping it.

3: When putting it all back together use a genuine nissan thermo, its only 10-15 from courtesyparts.com . Also Remember to TAKE YOUR TIME. Have the front of the car jacked up when filling the coolant, climate control on full hot, bleeder valve open, fill till fluid comes out of the bleeder constantly. Then close it and fill to the top of the rad.

4: Drive the car around and religiously check your oil and coolant to make sure the head gasket is seated right.

Good Luck!

[Nathan]

Thats exactly how the head gasket should be, I've asked the same question myself before. The reason it's that way though is to promote the flow of water all the way through the block to the back, and then all the way through the head back to the front of the motor. If it wasn't like that, the water would stagnate in the back, warm up, and cause you some major problems It's been flirted with to drill some SMALL holes in it, but I dont think anyone is daring enough to try.

[p00t]

i guess im wrong again then. its interesting to note how the head and blocks have passages along their whole length (from what i can tell). But only use those rear ones. You think its possible that they over engineered the cooling system at first? or is there some underlying reason?

heres a pic that i found of the KADE gasket:

http://www.superiorgasket.com/HG-KA24E-91.jpg

heres a pic of the KAE gasket:

http://www.superiorgasket.com/HG-KA24E-89.jpg

[Nathan]

Yeah, it is pretty odd...I honestly dont know the answer but sure would like too! I just know that that IS how the stock headgasket should be, for the basic reason of promoting flow throughout the engine.