Cooling System Problems...please explain?

ok so i have a 98 with a 4.0 that has about 130k miles on it. up until now ive have no problems whatsoever with the engine. a couple weeks ago i realized i was leaking coolant from (what looked like) the lower radiator hose. my mom works for the corporate office for Bridgestone/Firestone, so i took it to their shop to have them replace the hose. They proceeded to tell that it was not the lower hose but the water pump was cracked.
Long story short...now they are telling me that somehow the exhaust and coolant are mixing (somewhere?). I am pretty knowledgeable about engines (aside from cooling systems i guess) and this is whole idea of mixing coolant and exhaust is new to me. Please someone tell me if A) this is actually possible and how so, and B) if someone has had the same problem how you went about fixing it...(to me that sounds like an irreversible problem)

any comments/tips/suggestions would be great...thanks!

You could have a blown head gasket or cracked block, but get a second opinion. I worked for BFS for 4 years, and not all their employees know how to use the "block checker" appropriately...

exhaust and coolant can "mix" the most common area is the headgasket, or cracked head, but I really doubt that could have an affect on your water pump, I'd prolly get a second opinoin.

thanks guys, thats what they told me was both the gasket and that i had a cracked cylinder head...would not both of these show signs somewhere other than the cooling system...like wouldnt i be able to tell from the engine performance or am i way off base here?

If you check the compression in each cylinder, that will give you a better idea of what is going on with your engine. If you have a blown head gasket or cracked head, you may not get the same compression in each cylinder. Both problems can be fixed with $$$. If it is the head gasket a shop can remove the head and gasket and install a new one. Same thing with the head. If it is cracked it can be removed and replaced. You may try to get them to clarify the cracked water pump. You may have just misunderstood them about that.

Let us know what you find.

cool thanks...i am supposed to be at work by noon tomorrow...we will see if that happens

i will let you know what i find out tomorrow


anyone have a Yamaha R6 they want to sell me? i need something to ride around while my heep is in the garage...not to mention i could make the monthly payment for less than the gas bill from the monster

A bridgestone/firestone repair shop, shudder at the thought, those places are the jiffy lube of car repairs. I''d put a padlock on my hood before I went in one of those places.
It's a 98, time to R&R the cooling system, pull the rad, water pump, hoses, thermostat, replace, I think I would also do the fan clutch while I had it apart too.

just picked up the monster...and they explained to me how they ran the block test and it seems as if everyone was right BLOWN HEAD GASKET..and possible crack in the head

now i have a few more questions for you guys...

first off...i drove straight from the garage to work (about 30 highway miles away) and for the first 15 mins or so everything seemed to be running as usual. about 215 degrees...and running fine. then out of nowhere (for the first time ever) the temp gauge rockets up to 260 and sticks there
so of course i pulled over...added some water...let it cool down, and went on my way

about 5 miles down the road it did the same thing

this time i let it cool for about 30 mins and finished the trip with no problems and a final temp of about 210-215

what would cause the random spike? is there something they used in the block test that would have maybe messed with the temp gauge or have caused the random spike in temp??

any help there would be great, id love to make it back home to my garage with a running heep.


NEXT, when i do the head job (haha) should i have the head thats on there now cleaned and re-done, or should i buy a new (or remanufactured) one? ive looked at prices and it looks like it would cost about the same to have mine redone as it would to buy one thats already done...


this is my first encounter with problems as big as this so any comments would be great! thanks alot...

oh and if anyone in the DFW area is looking for some slave labor...with free beer of course...let me know if you feel like coming over and wrenching with me haha

anyone got any ideas?

This can happen if you lose coolant and an air space is created where there should be coolant then the coolant circulates back to that area and it heats up really quickly.

ok so i guess my next question would be what am i going to do to the thing if i drive it @ 210-215...maybe 220 for the next couple of days until i can get all my parts together and something else to drive while i have it in the garage?? i suppose i risk warping the head...which i will most likely replace anyways...but what else am i risking here?

PV=NRT chemistry formula dealing with temp and pressure. solve for T=(PV)/(NR) Basically as the pressure goes up, so does the temperature (part of the reason your temp went up). A leak of pressure in the cylinder is going to raise the pressure in the cooling system - which causes leaks, and air spaces like doclouie said (the other part of the reason the temp went up). It will also cause cooling hoses to spontaneously burst. But that is also why radiator caps have pressure relief valves built in. Be sure you know what you are doing before you tear into your heep. The only reason to buy a new head is if the old one is toast. If it is not destroyed, take it to the local machine shop and have them freshen it up. Don't drive long distances either until it is fixed.

deisenba said:

PV=NRT chemistry formula dealing with temp and pressure. solve for T=(PV)/(NR) Basically as the pressure goes up, so does the temperature (part of the reason your temp went up). A leak of pressure in the cylinder is going to raise the pressure in the cooling system - which causes leaks, and air spaces like doclouie said (the other part of the reason the temp went up). It will also cause cooling hoses to spontaneously burst. But that is also why radiator caps have pressure relief valves built in. Be sure you know what you are doing before you tear into your heep. The only reason to buy a new head is if the old one is toast. If it is not destroyed, take it to the local machine shop and have them freshen it up. Don't drive long distances either until it is fixed.

Click to expand...

haha thanks for the chem101!
i just thought it was weird since it had never done that before, and i have been driving daily for the past couple weeks with what i thought was a broken water pump. also on the drive home tonight i had no problems...it never got any hotter than 210.

the only reason i mentioned having to replace the head is because i was told that it was most likely cracked...of course i would have to have it magnafluxed to find out for sure and thought that it would be just as easy and faster to buy a head that has already been through the whole process.

and again, i am new to this whole thing so i am open to everyones suggestions

thanks for everything so far

So far from your description it does not sound like a cracked head or head gasket. To prove it for sure have the exhaust sniffed then have the coolant tested, if it's head or gasket ONE or the other should come out positive. I would R&R the entire cooling system and then go from there.

so, what ever happened with this?

Think I would get a second opinion.... Sounds as though they are trying to sell you repairs that are not needed...
I would agree with Rich P's recommendations....
The cooling system needs alot of attention....