[09 R/T]

Recently my car started overheating after a short period on the road.

My initial hope was that the coolant reservoir cap was failing and any water was just starting to boil out. Replaced it and made sure to run any bubbles out of the system (heater took a LONG time to get heat back). I let it run in the driveway for a while at temp and it held stable. Once I got it out on the road and started putting it under a little load it seemed like it was going to be fine. Temps were going up and down like normal. Then after about 5-10 minutes on the road, babying it the whole time, temps just start going up. They keep raising until the coolant starts to boil again and once that happens there's no coming back. Need to shut it down and let it cool and then it will repeat the exact same 5-10 driving window.

So I next turned to the 180* tstat. Ended up getting a stock stat for now and put it in, raised the fan temps, got all the air out of the system, and let it run for a bit to see if it was even stable at idle with the hood closed. It did fine running in the driveway and was still able to hold stable temps. However, when I took it out it exhibited the exact same behavior.

At this point I figured maybe I've topped it off with water too much so the boiling point is much too low and that's where the issue is coming from. So I filled the system with just coolant (Plus whatever coolant/water mix was in there still). If I had to guess I would say it was at an 80/20 mix so the boiling point should be pretty high. Well I bring it out again and things actually seem like they will be fine. Then... this car once again did the one thing I've come to depend on it for.. Started overheating again. Boiling seemed to start later but it boiled none the less.

And that's where I am now.

The temp sensor was relocated on my car so its got me wondering if that may be part of the issue. Its now attached to a 90* that's going to the top of the water pump. I don't remember what temp it got to exactly before I stopped it but I'm pretty sure the sensor showed the coolant at 220* and oil at 245*. This kinda made me wonder if the sensor was the issue and the fans weren't coming on.. But that may not be likely because I've had it start overheating on the highway at medium speeds (45-55).

I also know there was some question about one of the head gaskets maybe going on wrong but we decided that wasn't the case and it probably went on right. I only bring it up because I'm getting white smoke on start-up and a lot of moisture coming out the tailpipes. I'm blaming that one on the overflowing coolant drenching the filter in the finder right under the tank. There's also no signs of oil in the coolant however there is a bit more floating debris and some sediment at the bottom of the tank. The floaters seem new or like they've started collecting quick enough to notice a difference and I don't really know if there was any sediment in the bottom of the tank before (its maybe a tablespoon of what looks like extremely fine dust).


What would everyone take a look at next?

Motor is a forged 5.7 at 9.75:1 and a 2.8l KB. Everything seems to be running alright... Its just the cooling system not being able to keep up.

 

[doc_shutin]

Do you have a pressure gauge to verify that you don't have a leak anywhere in the cooling system?

Also, might want to do a compression check just to make sure that a head gasket isn't an issue....just because it isn't completely blown out doesn't mean it's not leaking a bit.

Best of luck...I hate troubleshooting electrical and cooling systems the most...

 

[waumo]

The only time I ever had a vehicle with symptoms you describe it turned out to be a leaking head gasket.

That was before the days of the catalytic converter so it was pretty obvious from the exhaust smell that the white smoke was antifreeze being burned.
I don't know if the catalytic converter would mask that smell or not.

 

[09 R/T]

^^^
I have no cats

I'm pretty sure the smoke is coolant. I don't know what coolant smoke smells like for sure but I do know what oil and fuel smell like. It's neither of those.

Do you have a pressure gauge to verify that you don't have a leak anywhere in the cooling system?

Also, might want to do a compression check just to make sure that a head gasket isn't an issue....just because it isn't completely blown out doesn't mean it's not leaking a bit.

Best of luck...I hate troubleshooting electrical and cooling systems the most...

I'll hav to get the test equipment. This is an issue I've never run into so I don't have the tools for it.

 

[waumo]

Normal antifreeze is a sickeningly sweet smell unlike anything you would expect to smell from exhaust. I can't say for sure on the MOPAR HOAT.

 

[09 R/T]

I'm using yellow Prestone.

That's exactly how I tried to describe the smell to someone. It smells almost sweet to me.

 

[chukarboy]

Don't know if this helps but
I had a similar problem and took it to a radiator shop where they took off the cap and replaced it with a cap with a indicator on it. I think it measured carbon monoxide levels in the cooling system. It went from blue to green. This diagnosed the problem as the head gasket.

 

[rdrdr90]

+1 on that test, and that smell. View from cheap seats is head gasket.

 

[CaptnCrash]

First off, adding too much anti-freeze will cause some large problems, water circulation removes heat, anti-freeze does not. If anything you want to run a much higher ratio of water to anti-freeze, pure water being the most efficient.

The pressure in the system raises the boiling point, you don't need anti-freeze to do that. That's why you have a radiator cap with a pressure rating.

My suggestion, use the 180 TStat, about 80-90% water the balance anti-freeze, a couple bottles of water wetter or whatever.

I'd get an SRT radiator or at the very least have your existing one checked.

If you have a sweet smell in the exhaust with white smoke and no cats, you have water in the exhaust, probably because you cooked a head / gasket. I'd pressure test the system before you do anything. A quick look at the plugs may also provide some clues.

Good luck!
--CC

 

[RICHSRT8]

This guy is having the same issue with a Kenne bell over on the LX forums.I gave him some advice on the last post.
Slight Overheating Issue - Lx Forums | Dodge Charger Challenger Magnum | SRT8 | Chrysler 300 Forum

 

[Yogi Bear]

The only time I ever had a vehicle with symptoms you describe it turned out to be a leaking head gasket.

That was before the days of the catalytic converter so it was pretty obvious from the exhaust smell that the white smoke was antifreeze being burned.
I don't know if the catalytic converter would mask that smell or not.

I am thinking the same thing - its either burning or going in your oil

The other option is you may have a defective water pump ... maybe in a way where the impeller is intermittently not engaged to the drive pulley or something ...? Or a clog somewhere?

 

[crow]

Motor is a forged 5.7 at 9.75:1 and a 2.8l KB. Everything seems to be running alright... Its just the cooling system not being able to keep up.

How many miles on this engine before you noticed the problem?

 

[09 R/T]

I've got maybe 3k on the motor since the build. So around the 3k range.

 

[WyGoSlw]

If you don't have water in the oil then you're burning coolant. This is why you're getting steam out of the pipes. The coolant has to go somewhere if it's getting low, either in the oil or out the tailpipe or on the ground. It's gotta be a HG..

 

[[email protected]]

Okay dude. Take a deep breath.....you're not going to like what I have to say about this.....

For 18 months, I had your SAME EXACT problem. Replaced three t-stats, three reservoir caps, an ECT sensor, two fan assemblies. And STILL had overheating issues. I even replaced the coolant reservoir tank, and it still persisted. I NEVER had any water in my exhaust, and I NEVER had any coolant/oil mixed together. The only two symptoms I had were consistent temps north of 200* and whenever I pushed the throttle, I'd spew coolant out the blowhole of the reservoir tank.

I had some of the most predominant modern Hemi builders and techs tell me it WASN'T a bad head gasket, throughout the entire process. All the while my builder and fabricator (NOT the shop that installed my 426 stroker, mind you, we'll leave that name unmentioned) was telling me it was.

All these little tedious, minor, yet completely frustrating illnesses, plagued my Charger for a year-and-a-fuggin-half!!!! I hated the car, NEVER wanted to drive it. A ridiculous game of cat and mouse, that had me cursing up a storm for longer than I even care to admit. Spending unnecessary $$$, because in the end......IT WAS A HEAD GASKET. See pics below.

Here's a few shots of the block. The parts that are squeaky clean, are from the hot coolant that seeped out, and actually cleaned the block.

And here's the head gasket, same thing.

Here's my advice, and here's what I learned. Just get it checked dude. DO IT. Quit wasting brain cells and excessive amount of frustration like I did. I WISH I would have checked it over a year ago!!!!
I will also tell you, to go back in and re-torque your head studs. MULTIPLE people will tell you it's not necessary. If you ask any of the guys I talked to (best of the best) they'll tell you that's a waste of time. But after I got the car fixed, and it went through about 9 heat cycles, I went back in and re-torqued my head studs. And guess what I found???? YUP. Two that were about 3-5lbs. off. Ask me if it was worth it???

My thoughts are that because I never did that after my initial motor build and install, it progressively got worse, and turned into a bad situation. You might be early enough to go back in and fix your problem, by simply re-torquing your studs, and call it a day. I however, had to have my heads decked. You can dance around it all you want, and pretend it's not true. That's exactly what I did. But in the end, it won't get any better. Check your head gasket bro, and if I'm wrong, at least you'll have peace of mind.

 

[[email protected]]

I just went back in and read some of the above posts. You can call me personally to discuss this if you want bud. I don't wish what I went through on ANYONE. It will ruin your life. That might sound drastic. But if you love your car as much as I do, it will have an effect on your focus and daily well-being, lol. Call it what you want, but it freakin SUUUUUUUUUUUUUUCKS. You are more than welcome to PM me for my phone number and talk in person. I'd be GLAD help. This is starting off JUST LIKE my situation did.

 

[PWR_Andy]

Im with chase. Head gasket. If you end up replacing them, go with a quality cometic head gasket. I will sell them at cost to you to help out.

 

[VelocityBoy]

Andy is the man!

Im with chase. Head gasket. If you end up replacing them, go with a quality cometic head gasket. I will sell them at cost to you to help out.

 

[ironchallenger]

Andy check your pm's bud ...

 

[[email protected]]

Yup. Andy is a GOOD DUDE.