and now I'm overheating...

Morgonzo · Post by **Morgonzo** » Thu Oct 20, 2016 7:24 pm

On the way back from driving to a friends house, I notice the Temp gauge is at the upper range...(it had never been past middle before.)..and soon after that was touching red. Well I got off the hwy and pulled into a parking lot and shut her down. I had No odor of coolant, no white exhaust. Just a pegged out temp gauge. Now in the past week, i've drained the coolant, flushed with water and filled with a radiator flush/cleaner and water. I was directed to drive for 3 to 6 hours with the cleaner in. I will be draining it all tomorrow morning and replacing with real coolant.
After 20 minutes I removed cap and found water level right at the top.I filled the expansion tank with water and started her up. The temp gauge was back at the top of normal. I was a mile from home so with a continuous stream of prayers coming out of my mouth I drove her home real easy. I made it back with nothing catastrophic happening.
I'll be looking at her tomorrow but would anybody have an idea as to what caused this? thermostat shot? water pump? If I blew the Head gasket i'd know it from the billows of white smoke out the tail pipe right?

Admin: thread moved to L300 Technical forum.

Post by **Growlerbearnz** » Thu Oct 20, 2016 8:00 pm

If the entire cooling system overheated it would *feel* hot- I would expect you to have noticed when you opened the engine cover, or at least when you removed the radiator cap! From the sounds of it though the radiator wasn't too hot.

My first guess would be a stuck closed thermostat. That would cause the engine to overheat, but not let the radiator get too hot. I wonder if the coolant flush stuff has damaged the thermostat in some way? Or dislodged something nasty that's blocked the thermostat? I would try starting the engine while feeling the top radiator hose at the radiator end- it should get hot after about 5 minutes.

Blown head gaskets don't *always* result in visible steam out the exhaust, but they do usually empty the radiator, usually from the gases pushing the coolant out. If your expansion tank keeps overflowing then something's not right.

Morgonzo · Post by **Morgonzo** » Thu Oct 20, 2016 8:13 pm

Thanks for moving this to the right section. I'm still getting used to posting in the right place. When I opened her up after I got off the highway, the upper rad hose was hot...but not crazy hot. I've been running the heat on full blast as I drive to help flush out the heater core..so it's been really warm in the van. Hard to tell if it was from excess engine heat. I was able to take the cap off (with a rag) after a 5 to 10 minute walk to the other end of the parking lot. Looks like the thermo is the next thing to look at.

gezzza · Post by **gezzza** » Fri Oct 21, 2016 3:41 am

Check your viscous fan with the ole rolled up newspaper trick. My L300 was running hot last week, threw a tube of oil in the fan and it fixed her right up.

Morgonzo · Post by **Morgonzo** » Fri Oct 21, 2016 5:18 pm

Thanks for the reply. I can't test the fan properly right now because I have the batt disconnected, GP's out, and both rad hoses and the Thermostat out. Right now as it sits the fan will spin when I move it but does not continue to spin freely. When I stop moving it, it stops. I have a new Thermo on order from my ATL Mitsu dealer, and now will need to order upper and lower rad hoses. I have to go find those part numbers

Morgonzo · Post by **Morgonzo** » Fri Oct 21, 2016 6:10 pm

Also tested the Thermo in a pot of Boiling water and it opened up...and then closed when I took it out to cool. I'm still replacing it. Do they come with the gasket or do you have to order that separately? Maybe it's the water pump...should I be able to spin the water pump with the belt on and motor off? Because I cannot. I CAN spin it with the belt off, I had to take the belt off to be able to get at the Thermo bolts i'm gonna go googling for water pump diagnosis threads.
I'm loving doing this work..

Morgonzo · Post by **Morgonzo** » Sat Oct 22, 2016 8:38 am

Anybody know the cross reference Stant part number for the rad cap? I know I saw it on a page last night but it's all a blur and I failed to write it down..(I stayed up LATE..

) and I would like to try to source a replacement to see how it works. I pulled the block drain this morning and flushed it out with the hose. What do you guys use as a sealant on that plug? The manual spec's 3M 4171 but it's not at the store and I have Permetex blue on the bench. I'm tempted to use it, but will hold off till I find a solid answer either way. I also cleaned up a bunch or corrosion that was all around the top outlet of the rad. I had to cut the upper rad hose off to get at it. I used a Dremel to clean it up and sand all the corrosion off. Nice and clean but will have to get a new hose..and the local Mitsu place was not available to get it so...off to Rock Mount Imports. Two hoses and a Thermo gasket (how cheap to not include with the thermo...

) Now I'm off to put in my new GP's and GP rail.

Post by **Growlerbearnz** » Sat Oct 22, 2016 3:08 pm

There's a bunch of cross-reference numbers in the FAQ here: http://www.delica.ca/forum/viewforum.php?f=16

Partsouq.com lists the genuine part number as MR481218. Googling "Stant MR481218" brings up Rock Auto part number 10227- same as the Lordco part number from the FAQ.

Morgonzo · Post by **Morgonzo** » Mon Oct 24, 2016 11:27 am

Thanks, I knew I had seen it..I just could not remember where. I ordered the upper and lower rad hose plus the thermo gasket form Rocky Mountain Imports this morning. I will be renting the rad cap tester and the engine block tester from the local auto parts store when we get her back together to see what's going on. I'm gonna try to find a way to flush the front and rear heater core. Any tip's?
Got the GP's in..and was curious about the little nut that is at the top of the plug, screwed onto the threaded bit at the end. the originals did not have those nuts there...what would the purpose of them be?

Morgonzo · Post by **Morgonzo** » Mon Oct 24, 2016 11:37 am

also, I had to clean up the upper rad outlet with a dremel because of the corrosion on it. It is now clean but i'm wondering if the clean bare metal will pose a problem with the new rad hose in forming a seal? should I dress the metal with something? I'm also contemplating buying a new rad and just saying screw it....this one (the original) has seen some coolant spillage before, around the upper pipe and the cap..for piece of mind it might be nice to have a new rad and not have to sweat about it on long drives.

Morgonzo · Post by **Morgonzo** » Thu Nov 10, 2016 6:04 pm

WELL! She's Running!

I finally got the time to finish up the rad and thermostat and after filling the rad with fresh Zerex, key'd the new GP's on the new copper rail and PRESTO! over two weeks not running and low temps. Yes, I did a little dance of joy

Get this though, as soon as i key'd it on, the Temp gauge shot up. I had taken out the sensor to test it but found my multimeter broken so I just put it back in. The engine ran great, and I ran it till the heat came up in the vents (thermostat opening right?) ran it up to 2500 rpm's on and off and then turned her off and filled up the rad and overflow.
I'm ordering a new senser tonight. If that solves it then i'll be beyond stoked.

Morgonzo · Post by **Morgonzo** » Thu Nov 10, 2016 6:31 pm

actually i'm thinking the fan might not be working properly...when the engine was cold and running, the fan was on and i tried to stick a roll of blue shop towels in the fan to stop it but it did not stop. When the engine is off, the fan is from to move, not freewheeling. I have not had enough time to run it till it got real warm. Am I worrying about nothing?

ChuckBlack · Post by **ChuckBlack** » Thu Nov 10, 2016 6:42 pm

Hey mongo,
I had a leaky rad too and after multiple attempts reconditioning it I then decided to buy a whole new one. The rad came with the cap, and bought a new thermostat as well. I did a full flush last year and replaced the old conventional 50/50 green coolant for a better quality ELC which by the way reduced my engine EGR from 800F to 700+-50F which then was a great improvements! I've done 30000K so far and no problems. I've climbed all those bid hills between BC and Alberta and temp has never been above the half way mark and yes it work!

Believe me!

Anyway good luck with all your work.

BTW is in it great when all the work you've done makes a difference? Good job diagnosing the problem!

ChuckBlack · Post by **ChuckBlack** » Thu Nov 10, 2016 6:48 pm

When your engine is not running, your fan should turn and not free wheeling. It should have a slight resistance in it. As the engine gets warmer and warmer the apparatus between the radiator and the clutch fan will coil up and fluid inside the clutch fan will eventually shift into locking mode, hence lock the fan hub. Eventually, you don't want a fan to be locked on all the time since the fan itself uses lots of HP. It should be on only when the engine is hot enough!

Morgonzo · Post by **Morgonzo** » Thu Nov 10, 2016 7:33 pm

Hey thanks ChuckBlack, I'm hoping that this sensor is the issue. If a new sensor does not bring the temp gauge down i'll be back to the drawing board. It seems to be running great others than that. I just pulled the connector off the top of the sensor and the temp gauge went down to the bottom. I thought about going with a new rad, but it's not cheap and I wanted to be sure if mine was crap or not.