Coolant not flowing through the engine...could use help trouble shooting this.
 

This just happened this morning am I am at work posting this. So, I haven't had a chance to get in and check things out. I'd appreciate any tips or suggestions.

Here's the what has happended:

• Add Coolant Light/Beep came on two days ago.
• Checked the Radiator fill cap and couldn't see any coolant in the fill neck.
• Checked the Coolant reservoir and it was full
• NO VISIBLE COOLANT LEAKS OR COOLANT COMING OUT THE OVERFLOW TANK
• NO WHITE SMOKE OR SWEET SMELL.
• I added some more Evans Coolant
• Light Beep gone
• Drove to work the yesterday with no issues.
• After work, when I started my car the Add Coolant Light/Beep came one again.
• I decided to drive home while watching the temps
  The beep went away after a few minutes and my temps were normal. 84 C on the PFC, mid-range on the Stock temp guage. So I thought it might be a bad coolant level sensor.
• This morning, the Light/Beep never went away. I got about 2-3 miles from home before I saw the stock temp guage rise past the half-way mark toward "high". The wierd thing is that the PFC temp guage only showed 53 C.
• I pulled over at this point and shut down.
• Checked the coolant filler neck. No coolant.
• Lower radiator hose is soft with no coolant in it.
• Reservoir is full.

I had to drive it another mile to get it off the freeway.
I ended up just having the POS towed back home.

I have an aftermarket temp guage connected with a sensor located at the filler neck. That never got hot, since there was no coolant going through there.

Here are my relevant mods:

• Pineapple ported motor with enlarged coolant mods, and upgraded silicone coolant seals w/ 20K miles on it.
• Evans NPG+ coolant
• Aluminum AST
• Koyo Radiator

What do you guys think is the problem here? I'm guessing its could be one of these:

• Water Pump dead
• Belt slipping and finally broke off(i forgot to check this on the side of the road)
• Clogged AST
• Cooling System needs flushing

I just hope that I didn't cook my seals or warp my rotor housings. Man, if I need another rebuild I am seriously going to with an LS1 swap or sell the FD.

stuck thermostat?

I had somewhat the same problem, but mine has the ast removal kit installed. The plug on my radiator had worked loose enough to seep coolant. Pull off your bottom under-cover and check your radiator and ast hoses. No coolant on the floor of your garage in the mornings?

All those locations with no coolant in them? Are you sure?

If so, you lost coolant fairly quickly (leaky hose, etc.) and there's nothing to pump. The fact that the reservoir is still full could be a separate problem, or it could be that your leak was big enough that the cooling system can't pull a vacuum to draw coolant back.

Sounds like you are not recovering coolant from the overflow after the engine cools.

Keep an eye on the overflow reservoir. If it keeps getting fuller and fuller and yet you constantly have to top up the engine with coolant then coolant isn't being recovered back into the motor as it cools off. Usually the seals on the caps are the culprits, though a loose or deteriorating coolant hose can do the same thing.

I believe the low coolant sensor is telling the truth and you're losing coolant somehow. If the thermostat were stuck temps would skyrocket immediately after the engine warmed, not some point down the road after you've driven it. A stuck thermostat also wouldn't cause you to lose coolant until you actually started boiling it out.

I'm not to familiar with the EVANS, but I had a very similar problem.

Turned out the thermostat was stuck, wasn't allowing coolant the flow through the rad, engine would get hot, start boiling off the water in the coolant, buzzer would go off, car would overheat.

The easiest thing I could have done to test the system, was to remove the thermostat and drive it like that. I say remove, because I replaced the thermostat with a new one - and it was bad - masking the real problem, and forcing me to try other solutions.

That sounds about right

I forgot to mention that I am running a Zero PSI cooling system. I removed the rubber seal on the AST pressure cap. So, would changing the caps make a difference? I will have to try to

Thanks for the suggestion, I'll try removing the Thermostat and report back. Now, I just need to figure out which gizmo is the thermostat. Shop manual here I come.

It's zero pressure but the coolant still expands and enters the overflow when it gets hot. As the engine cools the coolant should be drawn back into the motor. If the seal under any of the caps is bad or a hose is loose etc as the engine cools it will suck air rather than coolant.

If this is happening the overflow will get a little fuller each time the engine is warmed up, shut down and then topped up again because the expanding coolant will keep filling the overflow but never make it back into the motor. You then "replace" that lost coolant in the motor by topping it up and it just loses it to the overflow again when the engine gets hot.

If the overflow does not continue to rise in level as you top up each time you most likely have an actual leak that only shows itself when the engine is hot.

Ahh, I see. Thanks for the clarification DamonB.
I just ordered a new thermostat and a radiator filler cap from Ray @ Malloy. He's running it over to Kinko's to Fedex it to me. Ray Crowe kicks ass! I hope that's it.

I think my 7 is sucking in air after a long drive and I think it's due to worn out caps. Any suggestions on what specific caps to get and where? Would my local Autozone or Advanced Auto Parts have reliable caps or should I order them online from a specific site?

An easy way to test is to see if your radiator is getting hot. if it gets hot, then the thermo is opening up and coolant is running though it. Or, just take the thermo out, and run it like that. taking the thermo out should only take about 10 minutes...

Ok, while I wait for Ray @ Malloy & Fedex to get send me the new Thermostat and the new cap, I took the thermostat out and tested it. The thermostat opened at 209-212 F repeatedly.

While I was removing the coolant filler neck the 3/8" coolant line to the Aluminium AST tore right off. So I'm guessing that that is where my defect was. Maybe that is where my coolant system was sucking in air.

So, I'll be waiting until I get the new cap and thermostat from Ray/Malloy and I'lll also be buying a new 3/8" coolant hose. I'll report back.

.

Hey John, a properly functioning T-stat should start opening around 85-86C (185F) and should be fully open by 95C or so (203F). Sounds like your t-stat might be opening a little higher.

Thanks Tyler,

Tha't good to know. If it was opening at a higher temp. It may have been stuck as well.

I'll be switching it out with a new t-stat. I hope Fedex gets here today.

Update: Changed Thermostat, hoses, & both caps
 

Ok, I changed the thermostat, the 3/8" hose from the filler neck to the AST, and both the AST cap and the flat cap on the filler neck. I also found small tear in the 3/8" hose from the AST to the Reservoir tank and fixed that.

I used a siphon/pump and moved the coolant from the reservoir tank into the coolant fillerneck(engine). I then warmed the car up and drove it on the freeway for a while. Temps were good/normal.
OEM guage read just below mid-point, Aftermarket temp guage w/ sensor in the filler neck(radiator temps) read 150-160 F & the PFC read 84 C.

I then parked her and had some left over thanksgiving dinner and restarted her. Coolant light/beep were on. Damnit! I then jammed a funnel into the filler neck and added yet more coolant. I reved the engine and saw the dreaded champange bubbles.

I am not seeing any white smoke from the exhaust and there isn't the sweet smell of burning coolant. Maybe Evans NPG+ doesn't burn white in the exhaust or smell whne burned...

So I am hoping that my seals are intact. But when I revved the engine, I saw the more bubbles. So air is getting sucked into my system somewhere. I will try bruping the system tomorrow AM.

Is there a good way of checking for leaks in the coolant system?
Where are common places for the system to spring leaks?
How can I check if the caps are leaking?

Pressure test it. Basically a small bicycle air pump that seals onto the radiator neck (AST neck in the case of the FD). With pressure in the system the coolant will be pushed out at the location of the leak. If it is your o-rings then coolant will enter the engine (pull the spark plugs while turning engine over to check). If it's a hose, heater core, radiator etc you will see a visible leak or hear air escaping.

Any garage should be able to do it if there is someone you use.

Zero pressure coolant means that there is no pressure to force coolant into the combustion chambers, and therefore, you will likely not see white smoke or smell coolant in the exhaust. This, however, also makes it easier for an o-ring leak to allow combustion gasses to displace the coolant.

So, unfortunately, this scenario fits your symptoms.

Here is another option.

It's the same tool Autozone has for rent. If you have a stock AST, you'll need to get something like the Stant #12027 adapter to test the system. The adapters in this particular kit will only test the caps.

Dave

Thanks guys,

I did get under the car last night and replaced the lower AST cap seal, allowing the pressure to build in the system. I then ran the car to get the coolant flowing. I checked the upper and lower radiator hoses. Those look pretty good. I did however, see coolant leaking onto to the floor (pretty fast drip) on the driver's side. I couldn't see exactly where the leak was coming from. The coolant collected and dripped from the subframe on the driver's side of the oil pan. I had a light up in there and I still couldn't see the actual leak.

I'm stumped. Do you guys think that the waterpump could be leaking or the TB? Any ideas?

I would check the little fucker of a hose under the throttle body and the big J shaped hose from the heater core that goes down along the firewall and into the block.

When it rains it pours...

Did you check the throttle body coolant lines? One comes across the back of the motor to the top of the throttle body. The other is a short hose with a 90 degree bend that is directly under the throttle body and leads to a hardpipe that travels to the front of the motor. Also check the heater hose that attaches to the engine just below the oil filter pedastal. These are the only locations coolant is present on the driver side of the motor.

DamonBQuote:
Originally Posted by jpandes
I did however, see coolant leaking onto to the floor (pretty fast drip) on the driver's side.



Did you check the throttle body coolant lines? One comes across the back of the motor to the top of the throttle body. The other is a short hose with a 90 degree bend that is directly under the throttle body and leads to a hardpipe that travels to the front of the motor. Also check the heater hose that attaches to the engine just below the oil filter pedastal. These are the only locations coolant is present on the driver side of the motor.



alberto_mgI would check the little fucker of a hose under the throttle body and the big J shaped hose from the heater core that goes down along the firewall and into the block.

When it rains it pours...


Thanks guys. I'm going to climb back under there again to check these hoses out. I'm printing out the service manual (cooling system) now. Also, I talked to a mechanic who mentioned that a rotor housing external sel may be leaking? I have never heard of this happenin

All these on the driver's side are pretty easy to get at, I would think if you remove the intake elbow and piping you should be able to see everything with a shop light. If it is the seals are you still thinking of going this route >http://www.craigslist.org/sby/pts/113214946.html?

I had that problem, and ^ was the culprit. I replaced all of my coolant lines and got a new AST, bam problem fixed.