Thermagasket

[Kev]

Originally Posted by Ranger

Don't reengineer the system. The only way a thermostat is going to help an overheat problem is if the thermostat itself is causing it. Otherwise it is just a band aid and will cause other problems. Use what was designed and tested at the factory.

Amen to that!

[Ur7x]

This tread keeps coming back like a bad case of Herpes...

Might I respectfully suggest that if we are going to talk about thermostats, plugged radiators, heater cores, belt tensioners, etc. we start new threads...

Unfortunately any useful information in this thread is lost in the random, albeit somewhat related items....

I think it is safe to say that Thermagasket as a fix for blown Northstar head gaskets, probably isn't going to work... Too bad... It would have been nice to know that a low cost cure exists to the $3000 problem that plagues some of our cars.

[rfishing]

I just spoke with the expert mechanic again these are his answers:

1. Block test is only good at the time they do it. Going down highway or up mountain the test might be different. Since I had 2 negative tests in past, the head gasket is probably opening up under load on highway only.

2. Temp is averaging 208 now, was 199 before taking it in. This is normal, and means cooling system is probably working better than before allowing temperature to get up higher. The new Tstat is AC Delco.

3. He recommends replacing the engine at this point vice repairing head gasket. Bases this on his experience with people adding stuff to engine. Seen it get back into the radiator again, and only way to get rid of all of it is bake out engine or something to that effect, and sometimes that does more damage to engine block as well. Keep in mind nobody in this area will work on my engine anyway.

Last night I drove the car and it did great. I drove around the neighborhood doing 30-40mph temp averaged 207-208 heater on or off did not mater in econo mode only. On highway for a few miles slight incline and few miles declines at 70mph temp was 200-207. On exceleration it did sound different throaty sounding. This morning I checked and coolant level is normal.

If all else fails, I will probably keep the car for local grocery store trips. I will attempt one more mountain approach before replacing engine, or selling car as mechanic special. I will check radiator again with laser thermometer as requested.

Just an add on note: He did state that my cooling system has good circulation, that he watched it flowing in Surge tank.

[donwon]

Originally Posted by Ur7x

This tread keeps coming back like a bad case of Herpes...

Might I respectfully suggest that if we are going to talk about thermostats, plugged radiators, heater cores, belt tensioners, etc. we start new threads...

Unfortunately any useful information in this thread is lost in the random, albeit somewhat related items....

I think it is safe to say that Thermagasket as a fix for blown Northstar head gaskets, probably isn't going to work... Too bad... It would have been nice to know that a low cost cure exists to the $3000 problem that plagues some of our cars.

I for one think this is a very helpful thread.
I have read it from start to finish 3 or 4 times.

I put the coolant tabs in this evening and thought I was gonna have the same problem as before. I think it stopped up the inlet side of mu radiator.
The hose from the Tstat would get hot and full of pressure.
I opened the cap enough times to let the pressure off and coolant
started circulating again.
it is ideling between 188 and 206.
Gonna drive around soon as I wash up and see how it does.

[rfishing]

This is a long shot...

I understand that on some years the overflow tank had issues with radiator caps not sealing properly. My 94 was replaced after the head gasket job a year ago, so how can I tell if I they gave me one of those tanks? What should I be looking for? A picture would be great.

Is there any harm in putting an 18 lb cap on vice a 15?

[Quadrasteer]

What ever happened to SJWOODRUFF? Did I miss his results when going through this thread? I also want to add that I used Bar's Head Gasket Repair and it lasted around 15 minutes.

[mtflight]

Originally Posted by rfishing

This is a long shot...

Is there any harm in putting an 18 lb cap on vice a 15?

At this point--what do you have to lose?

[denscor]

can't remember, but I thinking lower psi cap it runs hotter higher runs cooler my want to check to make sure! I also think the cap is a 16 psi. Like I said may want to check it out!

[mtflight]

Originally Posted by denscor

can't remember, but I thinking lower psi cap it runs hotter higher runs cooler my want to check to make sure! I also think the cap is a 16 psi. Like I said may want to check it out!

Hmmm in theory, the accomplishment is increasing the temperature at which the coolant will boil. This could also mean that it would prevent the coolant from coming out of the overflow hose.

Temperatures in the cooling system should remain the same as they are currently, with the exception of not losing as much coolant to the overflow hose.

I'm no mechanic or backyard scientist. This is merely speculation and should not be used as science. I should not be held liable for expressing my opinion, of what could happen.

[denscor]

Try it and see!!!

[Ranger]

Raising the cap pressure will raise the boiling point as well as (obviously) putting the system under greater pressure. It will not fix a bad head gasket. There is only one fix for that.

[rfishing]

Radiator temps:

Before driving, I wiped radiator cap area off real good, and inspected it. Not much I can see that would cause any problem. I only drove about 8 minutes, then while at idle took these readings, dashboard displayed temp of 200.

Radiator on upper hose side is basically hot, and on opposite side is cold. At least 50 degrees cooler on the entire lower hose side.

-Upper hose nearest to engine is 178, but same hose at other end nearest to the radiator was 160, why so much difference? As engine temp went up the difference became within a few degrees.

-Lower hose only 74 degrees, what is going on here? 100 degrees diff between upper and lower hoses. I think answer is, thermostat didn't open yet? Or is just starting to open?

As engine temp display goes up to 212, cold side of radiator starts feel warm, and lower hose and upper hose temps begin to have less difference in temps.

At 223 degrees upper hose was 202 and lower is 204. Entire radiator is warm to touch.

At 225 degrees I revved engine up to 2500rpms for a minute, and temp started to come down. Prior to getting radiator rod out, If I did that, the coolant would overflow out the overflow tube. This time everything is sealed tight, no overflow leaks.

When temp was on way up and at 216, I took it out for low speed drive, and soon as I excelerated the temp quickly came down to 207. Driving 30-40mph it seems to stay near 207. Pretty much same temp as the other day.

Correct me if Im wrong, but taking temps on running engine is probably not the right way. Would be better to allow temp to reach point of tstat opening, drive it 5-10 minutes, stop engine, then take readings. That way, you get a snap shot, not a changing temp pattern. Getting a good reading with engine running is difficult, and is quicker and easier to use your hand.

Where is the temp sensor for dashboard display? When I scan engine, hottest temp I can read is at the hose housing area. With dashboard temp showing 200, hottest part I could find was 170's.

Just for giggles, exhaust temp was 155 on passenger side, 145 drivers side.

Oh by the way, I found an engine with 67k miles in Dallas, with shipping they want $1000.00 but warranty only covers parts, not installation. No telling what condition its in. Installer wants 1700 +++

[C170B]

Dear rfishing

I sure wish there was some way for you to get over the mountain w/o overheating/ venting coolant.

What temp do you get up to and does the stop engine light come on?
When you go up the mountain is your transmission in "D" or 3RD?

I am disappointed in the cooling design of most N* and am sure they have a redesign in newer models to be introduced. The purge line running to TB to heat it in case of "icing" seems be wrong engineering. Plus the surge tank is a pressurized tank integral to cooling system and when it over heats coolant is expelled to the atmoshere through that little tube on side of tank. Coolant is gone forever.

On a diff web site there are big eng classic owners who state "older cars become less efficient in cooling system and overheats can occur". An aftermarket company is producing a complete line of "overflow" tank of Billet Aluminum w silicone hose . Same principle as as the old white plastic overflow bottles, when it overheats and expells coolant , then cools down and the coolant is returned to radiator and not lost! The big point they seem to make is that if there is no air leak the radiator is always remains FULL!

Is it possible that a similar system could help a N* w small headgasket leak drive another 50K miles? I don't know but I am wondering about additional cooling capacity.

[Ranger]

The Northstar cooling system is plenty capable of doing the job for which it was designed, if it is in good condition. Increasing cap pressure, adding overflow tanks or repairs in a bottle etc. will not cure a bad head gasket. The surge tank is essentialy an overflow tank. As long as there is coolant in it, the radiator is full. The head gasket will eventually get worse and it will overheat all the time. At some point you will have to abandon all hope and accept the inevitable. The heads must come off, the block Timserted and the gaskets replaced.

[Quadrasteer]

Bump, bump.....[quote=Quadrasteer]What ever happened to SJWOODRUFF? Did I miss his results when going through this thread?