Need help overheating again

[charge1]

Just put a new TCI manual valve body Tranmission in the car and it started running hot again I had an overheating problem before and it turned out it was a bad cap. I replaced the cap, replaced the thermostat 180 adjusted the timing 16* (initial) Temp guage now fluctuates goes to 205 then drops to 150/160 while idling it will get to about 190 the after a short drive maybe 10 miles it just starts to creep up, if i shut the car off it just starts spewing out the overflow with alot of force. I have a new griffin rad on order and will be running a 5 blade clutch fan with a shroud.

I thought maybe a head gasket but i dont have any other symptoms than the fluid is foamy but not oily when cold there are no signs of oil on the cap or in the oil, I checked for co2 in the radiator with the test kit from napa and nothing stayed blue, and the plugs look good.

any ideas

Thanks Bryan

[Musicman]

Actually it sounds like a bad cap... lifting at low pressure... what's the pressure rating on it, maybe it's to low. or maybe it's faulty.
I had a brand new one fall apart on me recently.

[charge1]

I just got it replace that with the thermostat not a high dollar one but brand new 16lb

[Musicman]

Wouldn't hurt to try a different one... Caps are cheap 
Be sure it seats good too.

[charge1]

Your in CT also arent you? Know any good speed shops Im at the end of my rope with this car I think I need a proffessional

[bobs66440]

Musicman is right about the cap. It seems to me that 190 deg. or even 205 deg. really isn't that hot. The coolant definitely shouldn't be boiling at that point. The only reason for coolant to spew out of the overflow (past the cap) is if it is overheating and creating excess pressure (which it doesn't sound like) or the cap is bad...or the head gasket is blown and compression is getting into the cooling system.

Are you running aluminum heads? If it has overheated too many times with aluminum heads, a head gasket leak is very possible. They expand & contract at different rates from cast iron and tend to promote damage to the gasket. I think the best way to check for a head gasket is to pressurize the cylinders and check the radiator for bubbles. That will tell you.

The new thermostat could be bad also. It has happened to me. I found out that NEW doesn't necessarily equal GOOD.

Perhaps more importantly, I also found that if you are having a stubborn problem that is driving you nuts (as you mentioned) sometimes it's just easier (if you can afford it) to pay someone else to deal with it....to preserve your sanity!!! I'm taking that approach more these days. 

[Musicman]

Yes my house is in CT, but I have been in the south working on a road job for the Navy for the last 2 frigg'n years... I'm actually getting on a plane tomorrow morning and heading back home to CT for a few days though.

I wouldn't sweat the overheating issue to much just yet... From what you've said so far, your engine temps haven't been high enough to justify a cap blowing it's top, unless it's a bad cap or it's not seating well. Sounds like it's boiling early... I would just look at the simple stuff first.

[bobs66440]

... I would just look at the simple stuff first.

[charge1]

I'm losing my mind with this car and nothing is simple any suggestions would be appreciated

[BigBlackDodge]

Are the hoses in good shape and not collapsing?



BBD

[bobs66440]

I'm losing my mind with this car and nothing is simple any suggestions would be appreciated

I would try, as Musicman suggested, a new cap. Stant makes good ones. I think 14lb. is most common for street cars, and the higher the pressure rating, the higher the boiling point of the coolant. Race cars generally use caps in the 24lb. range. But it also puts extra pressure on the system. Good thought about the hoses, BBD. Then you could try a new thermostat. If everything checks out then move on to the more complicated stuff.

[elacruze]

Sounds like you have air trapped in the system.

Trapped air will heat up and create a lot more pressure than coolant and can overcome the pressure cap.
With the engine cool, remove the cap, rev the engine up as high as you're comfortable with for 15-30 seconds. See how much the water level drops after a couple rounds. Squeeze your top radiator hose a few times too, to help push any air out that's collected in the high point.

[charge1]

Well I jacked the car up let it run for a few minutes and I heard a gurggling sound like air so hopefully this fixed the problem  Going on a cruise tommorrow we will soon find out

[Cooter]

Keep in mind that most newer cars run around 227 Degrees BEFORE the electric fans even come on...This is with aluminum heads/blocks...200 Degrees just seems hot because we are so used to hearing the old timers talk about 160 degrees all day long...Once you overbore an engine, up the compression ratio, etc for better performance, the temp will increase as well....

I have had three 440's that I built and only the one that I didn't overbore and has hardly any compression runs 180 degrees all day long...The other two I "Built" and they both will hit 210 Degrees on a hot day...Also, hardly anybody checks to make sure their pulley set up is the correct ratio either...I myslef, have made this very mistake..Like running A/C water pump pulley with NON- A/C crank and it spins the water pump too fast...Another area where people fail to reallize the "Error" is "Four row" radiators will actually cause the engine to run a little warmer than say a 3-row or even an aluminum 2 row(1" cores)...Up and down, Brass/copper stock style radiators are very ineffient to say the least, but do work..However, a nice Aluminum 2 row CROSS flow will cool a bit better....