DOHC running warm...Then DOHC running cool...Then.

[gpse3400]

let us know.

[1994KlrWhaleOlds]

I shall.

[dohcfiend]

sounds like a head gasket. My old z34 done the same thing. it fluctuated some then it got hotter and about a week after that it gave out completely and starrted bellowing plumes of white smoke.

check for cross contamination. when you pop your rad cap, do you seen any nasty white crap in there or something that looks like soot? with the car running, when you pop your cap, do you see any bubbling?

[1994KlrWhaleOlds]

sounds like a head gasket. My old z34 done the same thing. it fluctuated some then it got hotter and about a week after that it gave out completely and starrted bellowing plumes of white smoke.

check for cross contamination. when you pop your rad cap, do you seen any nasty white crap in there or something that looks like soot? with the car running, when you pop your cap, do you see any bubbling?

Absolutely no bubbling, no white crap, just green coolant in the rad.

After changing the cap, I'm happy to say that it went to 190 and stayed there the way to see Taylor and back.

[TDIXON]

that should b fairly normal its your tstat opening and closing when the temp rises and lowers. once tstat opens temp lowers then colder fluid hits tstat and it closes until temp heats up again and contiually repeats process.

[1994KlrWhaleOlds]

Well, shit.......Temp gauge went way up this evening again...I think I need to get another style of water pump, who sells the old style now??

[gpse3400]

If you are running that newer pump that would be your problem... it is insufficient for that engine unfortunatly the aftermarket doesnt think so. When you get another pump try for a reman, it should have the old iron impeller on it. Otherwise go to the yarde and get a pump out of a 3400 or something. They are all the same.

[1994KlrWhaleOlds]

I'll change it back this weekend.

[1994KlrWhaleOlds]

If you are running that newer pump that would be your problem... it is insufficient for that engine unfortunatly the aftermarket doesnt think so. When you get another pump try for a reman, it should have the old iron impeller on it. Otherwise go to the yarde and get a pump out of a 3400 or something. They are all the same.

That was it I'm certain this time)! I drove it for about 3 hours on the freeway and sitting in traffic and the temp never went above 190° the whole time. Lorenzo: I could kiss you!!!

[gpse3400]

Easy killer! I am happy to help out!

[1994KlrWhaleOlds]

[series8217]

Wow. That "new" style pup looks terribly inefficient. So few vanes and they aren't even as long as the original style ones..

[1994KlrWhaleOlds]

On the left, we have the typical junk sold by auto parts stores. The aftermarket seems to think this will work on a DOHC 3.4 and it WON'T. On the right is the original 3.4 DOHC water pump...And what you should get - a remanufacturered pump.

[bszopi]

I just put the same type of replacement pump in my 3400. I too was kind of sceptical about the new design, but didn't think much more about it. Until now...

[gpse3400]

It doesn't seem to affect the pushrod engines. I'm thinking its somthing with the housings on the front covers.