HIS S-197

Need a little help troubleshooting the coolant system on my wife's '07.
She through a belt and overheated yesterday, steam billowing from the engine bay (we've all been there).

I replaced the belt and topped off the coolant in the expansion reservoir thinking that may take care of the problem however after running the engine for a bit I noticed some steam from the engine bay. There was no puddle under the car and the t-stat gauge was just before 12 o'clock/normal operating temperature so we limped it home (5 minutes, just under 2 miles).

I checked on it this morning and noticed the level in the reservoir was lower (from the MAX to just below the MIN cool-fill line) but no puddle underneath the car. So I let the engine run for a bit checking for leaks in hoses and of course at the plastic t-stat housing. The engine isn't overheating and I don't see any fluid leaking anywhere but there is definitely steam, not a lot but it's there if you look hard enough.

I think it's coming from the radiator but it's hard to tell.
I doesn't seem to be coming from t-stat housing.
I checked the oil and it's not milky and no white smoke from exhaust... REALLY hoping it's not a blown head gasket.

I suspect the radiator may be blown but I'm not sure.

Any thoughts/suggestions/help/sympathy/prayer is greatly appreciated.

NOTE:
I've already got plans to swap out the plastic t-housing in both our cars with the metal option on eBay/amazon.

kevinmalec

I have an external head gasket leak and the coolant is dripping down into the "V" of the engine and setting in there. Once it gets really full, it starts leaking out onto the ground. Due to being external, the engine is not in any danger. I replaced out the cracked upper/lower thermostat housing over a year ago and is still working fine with no leaks.

66and06stangs

I sympathize at least brah....

Siber Express

Just wondering if it is leftover coolant on the outside just steaming away. It would seem if the radiator was gone it would leak. Coolant takes awhile to evaporate.

HIS S-197

Thanks for the feedback!

I had the wife's car pressure tested and the shop said the expansion tank cap wasn't holding pressure (it leaked at 11 psi instead of 17 psi). So I got a new one.

I haven't had a chance to drive the car myself to be sure if that really fixed the issue since we were out of town this weekend. But the wife hasn't driven it the past few days to and from work without incident. No overheating or puddle under the car.

Where exactly is the external gasket you had issue with?
Was it the gasket between the upper and lower t-stat housing?
I haven't noticed the t-stat housing leaking but I may need to take a closer look.

I was thinking/hoping the same thing.

If it was just left over coolant, the radiator cap was covered under my wife's extended warranty so it didn't cost me anything extra on top of the crankshaft pulley/harmonic balancer they were also replacing under warranty.
I only paid a $50 deductible for parts and labor.

HAHA, Thanks. Everyone likes to know they're not alone.

Nuke

Don't base your determination on the car sitting for a few days undriven. A leak will show itself under pressure but may not after the engine cools and the pressure dissipates.

HIS S-197

Thanks. I didn't solely rely on letting it sit and not seeing the puddle under the car.
Before the repair, I was letting the car idle until it got to operating temperature.
Only after it spent a few minutes at normal operating temperature did I notice the steam and coolant smell.
The shop also pressure tested the system and said the only source of a leak was the expansion tank cap.

I'm thinking the problem is gone as my wife or I haven't noticed the coolant smell.
I've only been under the hood to do a quick check of the new pulley/belt alignment.
Save for a metal t-stat housing swap in the near future, I think it's squared away.

kevinmalec

In reference to the head gasket leak, once the engine is on and idling for awhile, I was able to see the coolant dripping out of the head where the bolts are. The bolts are located on the engine behind the thermostat housing (top near V section of engine).

When my t-stat was leaking, it was leaking coolant in between the upper/lower housing (back side). The heat warped the t-stat housing; thus causing the leak.

Good luck!

157dB

My T-Stat housing started leaking and I just loosened the
cap to let the system build zero pressure. The leak stopped
and I drove her like a bat outta heck for 2 years before the
thermostat housing started leaking again.
On the back side from the seam. From the engine heat??

I do not think the 11 psi instead of 17 psi is the problem.
He sold you something you did not need.
The system needs to be purged of any air when the coolant
gets low enough and you start adding coolant.

Once you start getting the coolant smell, it does not disappear
right away when the leak gets fixed unless you clean ALL
of it from the engine and engine bay.