SR20DET is OVERHEATING while idling on the DYNO!!

[QuinGarcia]

So guys, I have a stock SR20DET with electromotive fuel injection on the dyno, and I soon plan to tune it. I bought the engine used from a guy in Long Island for about $1300 and it has proven to be high mileage. I am overheating. The baseline tune on the fuel injection is off, but I dont think it would be causing my engine to overheat on the dyno. I am not running a heater obviously as the engine is on a dyno. I just have the two heater hoses at the back of the engine connected to each other. I have the main radiator hose on the driver side of the engine (same side as exhaust manifold) connected to the top of the radiator. I have the main radiator hose on the passenger side of the engine ( the hose that connects to the thermostat housing) running to the bottom of the radiator. I am running hot for some reason even though I am just lettting the engine idle at about 1500rpm for about 20 minutes on the dyno. I have a toyota downflow radiator and electric fan with the stock toyota overflow tank. I just bought a new 170 degree thermostat and installed it because the old thermostat wasnt working when I bought the engine. The heater hoses that are at the back of the engine (the ones that I connected to each other to delete my heater) aren't even getting hot, but the rest of the engine is getting really hot. Too hot!!! I thought those heater hoses should flow coolant even before the thermostat opens? Apparently they are flowing little to none. The radiator cap (stock toyota 13 psi in crappy shape, but seems to be operating) was below the level of the heater hoses in the engine, so I figured there was an air pocket in the top of my cooling passages (the engine had no coolant in it when I bought it). So I raised up the radiator so the cap was higher than the heater hoses, ran it, and still the heater hoses aren't getting hot, and the engine is overheating. Help? Am I bleeding it right? What could be wrong? Is my water pump shot?? What tests can I run?

[I H8 UR DSM]

I'd change the water pump. It 'should' be changed either way.

[Cattalbus]

I guess my only question for you is why all the toyota pieces? is this going in a nissan?

[yellow_jacket]

I agree, change the water pump out. On occasion I have seen motors then after sitting the blades on the water pump rusted and were partially gone. Of course this caused overheating problems.

If the rest of your cooling system is fine you should be able to run w/o a heater no problem. The only time running the heater should make a difference is if you have other cooling system isssues.

If all else fails, try running it without a thermostat and see if you still overheat.

[martin]

My guess is it's the head gasket gone. Do you have an overflow tank connected to teh system? Is the coolant getting forced out and into the overflow tank? Is the top rad hose really hard (under lots of pressure)? Like I said I think it's the head gasket, I'm waiting for one to arrive now, just gone through this.

-Martin.

[yellow_jacket]

It probably is the head gasket, especially on a higher mileage motor. You can run a compression check to help diagnose that.

As cheap as thermostats and water pumps are it is just way cheaper to check those first.

[QuinGarcia]

i dont think its the head gasket cuz the engine runs ok. Secondlt I ran a compression test and no cylinder got below 135psi. So the compression ring on the headgasket is definitely not blown. I replaced the thermostat with an aftermarket replacement that opens at the same 170 degrees F as stock does. How much is a water pump, and where can I get one for cheap that is good? Do really need one? The reason why Im running the toyota stuff is cuz it was laying around the shop. The engine will be going in a 2002 Ford Explorer XLT and will be coupled to a 200hp electric motor as well. thanx

[slw240sx]

ahhwhaa a ford explorer?? ....why.... ....sigh.... .....why......stares blankly and walks away......

[MojoMan]

waas is das finken shist!!!!!:jump

[MojoMan]

I hope your not the one doing the install. And besides if your fuel management is off you can run hot. Besides where are you getting a 200 hp electrical motor to begin with and what kind of money are you lookin at spending to butcher the poor already helpless ford. Let it die with dignity. OOHHHH IS THERE NO MERCY?

[MainEvent212]

can u run JUST the electrical motor? cuz i'd rather have a 200hp electric 240sx than a 140hp gas guzzler...

hehe the sr can wait till after highschool

[QuinGarcia]

Yes Mojo Man I am doing the install, and I will do it fine. What are you some kind of expert????? If so, why dont you impart to me the reason why I am having cooling problems. I also have this strange inkling that my engine wouldnt even frickin run if "my fuel management was off" as far as you suggest, sure if it ran lean under heavy load perhaps it would run hot, but I am just idling it at 1500rpm. If my fuel mixture was far enough off to make me overheat at idle, then I have a feeling that engine wouldnt be running decently as it was. Thanks for the snide remarks. I am part of a team creating a hybrid vehicle for competition at a National competition at Ford's world headquarters. Much of our parts are sponsored. And from your lack of intelligence so far, I probably wouldnt allow you on our team. Our truck has over 400hp, weighs 5500 pounds, and gets 25mpg. I bet you couldnt do that install, genius! And I bet our truck would get better mileage, and smoke whatever weak ricer that you have to offer. Any ideas on the cooling problem? Do you wanna help me or are you on this forum to try to act like you know your shi*?

[Nils]

Yes Mojo Man I am doing the install, and I will do it fine. What are you some kind of expert????? If so, why dont you impart to me the reason why I am having cooling problems. I also have this strange inkling that my engine wouldnt even frickin run if "my fuel management was off" as far as you suggest, sure if it ran lean under heavy load perhaps it would run hot, but I am just idling it at 1500rpm. If my fuel mixture was far enough off to make me overheat at idle, then I have a feeling that engine wouldnt be running decently as it was. Thanks for the snide remarks. I am part of a team creating a hybrid vehicle for competition at a National competition at Ford's world headquarters. Much of our parts are sponsored. And from your lack of intelligence so far, I probably wouldnt allow you on our team. Our truck has over 400hp, weighs 5500 pounds, and gets 25mpg. I bet you couldnt do that install, genius! And I bet our truck would get better mileage, and smoke whatever weak ricer that you have to offer. Any ideas on the cooling problem? Do you wanna help me or are you on this forum to try to act like you know your shi*?

Just out of curiousity.. how do you know that your truck has 400hp when it is over heating while idling on the dyno? Got a dyno sheet?

Your problem could be caused by numerous reasons, to hard to trouble shoot without seeing the truck/suv project since it is such a custom job.

n

[godspeed]

i think its cool what you are doing, good luck, sorry i'm no help, but i'm sure someone on here can help, just keep giving us info, i would like to see some pics of this, hell this is beter than a ford engine in a 240sx

[QuinGarcia]

Our electric motor has been dynoed at 200hp, and I think it should be pretty easy to extract the other 200hp from an SR20DET. If not more.......If I can just get the damn thing to stop overheating on me. Nils, let me remind you that the engine I am referring to is not even on the truck yet, so all I need to know is how to get the thing to stop overheating on the dyno. Once it's in the truck we shouldnt have too great a problem. thanx for the input fellaa, any other ideas?

[slw240sx]

a person with such resources as youself shouldnt have much trouble affording the replacement of every part of the coolant systm and then youll know what the problemn was just do it one part at a time... starting with pump and thermostat and then onto other various hoses and what not !! pressure test your cooling sytemn to besure you have no blockages.... maybe you blew the headgasket or its blown already ... this shouldnt take more then a few days to figure out !!!!

[martin]

i dont think its the head gasket cuz the engine runs ok. Secondlt I ran a compression test and no cylinder got below 135psi. So the compression ring on the headgasket is definitely not blown. I replaced the thermostat with an aftermarket replacement that opens at the same 170 degrees F as stock does. How much is a water pump, and where can I get one for cheap that is good? Do really need one? The reason why Im running the toyota stuff is cuz it was laying around the shop. The engine will be going in a 2002 Ford Explorer XLT and will be coupled to a 200hp electric motor as well. thanx

Well I ran a compression test too and got "reasonable ' results, but as soon as the motor got up to operating temps to was forcing compression into the cooling system.

I'd replace the head gasket and have it done with, especially given it's a high milage motor. $85 from Phase2. SR20DE gasket doesn't fit, I tried that route.

Since you've already replaced the t-stat it's probably not that, pull teh water pump off (it's only 6 bolts or so), check the blades, but I doubt it's that. A water pump will usually leak and squeal, but they hardly ever stop pumping.

I don't remember you saying how hot the motor is getting, do you have an accurate gauge on there? What is the reading?

-Martin.

[MojoMan]

Our electric motor has been dynoed at 200hp, and I think it should be pretty easy to extract the other 200hp from an SR20DET. If not more.......If I can just get the damn thing to stop overheating on me. Nils, let me remind you that the engine I am referring to is not even on the truck yet, so all I need to know is how to get the thing to stop overheating on the dyno. Once it's in the truck we shouldnt have too great a problem. thanx for the input fellaa, any other ideas?

The reason I question your ability is not because your a DIY but because of the questions you asked as if you didnt know what you were doing. And I wasnt the only one wondering this. Its like your acting like a rocket scientist and then asking "Does this shoe go on the left foot or right foot?" For a person to work in a shop and build some frankenstien you should know what to look for when overheating. Now I know it makes us all feel comfortable when we have problems such as overheating, h ell Iv'e asked questions to. But Im not the one working in a shop building some hybrid with a motor that you apparently dont seem to know to much about. Just look at your original post and the others you have and you'll see what I'm talking about. I know Iv'e asked stupid questions on occasion. But I dont work ina shop with other people to ask.

[I H8 UR DSM]

yea, not to knock anyone....but if the car is overheating, you run through the checklist of possible causes,,....there isnt much a message board or forum, who isnt there, and cant visually inspect the car, can do....we cant physically help you or diagnose your problems....if you cant diagnose it, you should consider taking it to a mechanic that can....i have never heard of a mechanic who couldnt figure out an overheating or cooling system problem personally....

but like i said, im not knocking you or anything....

[Nils]

Our electric motor has been dynoed at 200hp, and I think it should be pretty easy to extract the other 200hp from an SR20DET. If not more.......If I can just get the damn thing to stop overheating on me. Nils, let me remind you that the engine I am referring to is not even on the truck yet, so all I need to know is how to get the thing to stop overheating on the dyno. Once it's in the truck we shouldnt have too great a problem. thanx for the input fellaa, any other ideas?

lol... so you have "bench" dynoed it? I love 'estimates'... how about you get it running first, then dyno it, then scan and post the dyno... then throw around and brag about HP numbers on forums.

I also agree with Jessie and the rest. If you dont know how to figure out a cooling problem then maybe you should take the car to a mechanic... how do you expect us to know what the problem is without seeing the engine?

I would also like to point out that this is a sportscar forum. You should expect some negative comments back when you announce the use of a SUV and suck it in. Are you going off-roading in this vehicle?

Good luck 'fellaa'.

n

[MojoMan]

Im out:D

[I H8 UR DSM]

I have some pics of an SUV that MTS just added a turbo too, and runs sub 15's at over 90 mph : ) if anyone wants pics i can email them

[QuinGarcia]

sorry gentleman I havent informed you that I only ran the engine twice and noticed that it was heating up, I have not been in the shop 24/7 trying to diagnose this, I instead chose to come to you to see if there was some confused piece of japanese engineering that I was missing. Basically, I wanted your suggestions before I dive too deep into the problem. Is that so bad??To those of you who question my ability with this engine, you do it rightfully. I have never really worked on japanese stuff like this (eg. thermostat on the inlet to the engine) and I dont know the nuances of these motors. I am most definitely not tryin to act "like a rocket scientist", I am just trying to give yall as much info on my situation so you can diagnose. You must keep in mind that mine is a STUDENT team, as in NOT EXPERT team, and no, we don't have anyone in the shop to ask when we dont know something. If I had my choice we'd have an aluminum Small block chevy in this thing in a second, but I dont, so I have to deal with something I am not familiar with.I H8 UR DSM: The engine is on a dyno, not in a car, and I don't know of too many mobile mechanics in our area. The goal of our team is to learn, so taking it to a mechanic is ruled out, I need to figure this one out.Nils: would you say its unreasonable to expect 200hp out of a stock SR20DET??? I am not trying to brag, I just think its an easy assumption. Perhaps I will post the dyno numbers when I am done just to shut Mr. Mojo up. Remember Nils that the other 200hp will come from an electric motor which has already been dynoed. And, this is not a sportscar forum, this forum is called "SR20DET", and thats what I got. I havent seen too many posts about suspension tuning or brake performance in here, just engine talk. thanks for your help

SLW240sx: I dont have the money to replace everything as you suggested. If my headgasket was blown I would expect steam from my tailpipe, or excessive coolant loss, there is neither

All of You: Remember, I am out of my element, and I just came for advice, not to have me or my project ripped on. I am not knowledgable about ricers, so I came to all of you to ask. I instead am a chevy man, because its simple and plain that they just make more power, more easily. If any of you want to come to my chevy forum, I'm sure I could teach yall quite a bit about horsepower (not too many Japs in the 7-second range are there), not to mention cooling sytems. True, there are similarities between the cooling systems from the two manufacturers, but the way they act is not always the same. Get me in front a real engine bay thats make true power and torque (chevy), and I'll have your cooling problem solved quickly. thank you for all your wonderful advice, I wish an email of this length could be used to discuss technicalk topics instead of defending myself

[I H8 UR DSM]

dont know if your on FA, but this may or may not help you.

http://forums.freshalloy.com/u...art=1

[GodzillaFan]

All of You: Remember, I am out of my element, and I just came for advice, not to have me or my project ripped on. I am not knowledgable about ricers, so I came to all of you to ask. I instead am a chevy man, because its simple and plain that they just make more power, more easily. If any of you want to come to my chevy forum, I'm sure I could teach yall quite a bit about horsepower (not too many Japs in the 7-second range are there), not to mention cooling sytems. True, there are similarities between the cooling systems from the two manufacturers, but the way they act is not always the same. Get me in front a real engine bay thats make true power and torque (chevy), and I'll have your cooling problem solved quickly. thank you for all your wonderful advice, I wish an email of this length could be used to discuss technicalk topics instead of defending myself

wow... I dont think anyone here is going to help you anymore....

and yes it is a sports car forum read carefully Car Specific > 240SX and Silvia (200SX) > Engine Talk > SR20DET

and since you went ahead and made a fool of yourselfi question your decision to even use a sr20det... not only a waste of a sr20det in a POS SUV ...its not known for its gas mileage or efficiency.... and in a frankenstein project + standalone?? I imagine its even harder to tune a turbo car to get good gas mileage than it is to just tune for power. if you wanted a 4 banger, why not a NA honda or toyota motor.

your "200hp" electric motor isnt enough?? why?

[QuinGarcia]

I thank all of you who have actually tried to help me figure my problem out. You have been a great help! To the pretenders who are trying to boost their own egos by ripping on my project, remember that I am just a student trying to learn from a knowledgeable source, so go fuc* yourself. Have fun working at Jiffy Lube during the day, then coming home to stroke your ego on the internet. :ylsuper

P.S. Godzilla, you have been a great help to me in the past, but to be hoest I wasnt really getting much help from some of these guys anyway, I wish you or some of the other more helpful gentleman had joined this thread a while ago.

[I H8 UR DSM]

Gentlemen would be correct grammer ; )

[martin]

I thank all of you who have actually tried to help me figure my problem out. You have been a great help! To the pretenders who are trying to boost their own egos by ripping on my project, remember that I am just a student trying to learn from a knowledgeable source, so go fuc* yourself. Have fun working at Jiffy Lube during the day, then coming home to stroke your ego on the internet. :ylsuper

P.S. Godzilla, you have been a great help to me in the past, but to be hoest I wasnt really getting much help from some of these guys anyway, I wish you or some of the other more helpful gentleman had joined this thread a while ago.

Hmm... Well I tried to help, but you don't believe me that it's the headgasket. You also didn't answer most of my questions, or even say what temperatuer you are seeing and if it's an accurate gauge. BWT... just because you get 135psi reading on your compression test doesn't mean that the fire ring isn't leaking. Think about it, rolling it over on the starter vs a combustion stroke. You can thank me when you realize that it is the head gasket, I hope for your sake that the engine isn't installed at that point.

-Martin.

[slw240sx]

Im out as well, no use in talking shop with a person who doesnt get simple engine dynamics ! its probably not even over heating its probably just getting hot on the valve cover and the turbo manifold, LOL

[QuinGarcia]

Martin, thank you for all your responses, you have been very helpful. Im sorry I ddint answer sooner. My gauge was on the program I use to tune the TEC-3, and it is accurate. It was reading 225 degrees. I agree with you that running the engine is different than a compression test. I pulled the water pump today and noticed some surface rust on the impeller blades, but no endplay. It seemed fine to me, so I reinstalled it. The engine is the dyno, so I wont have a terrible time pulling the head off if it is the headgasket. I ran a leakdown test also and all the cylinders were moderate to good. Any methods that will positively tell me that it's the headgasket so I dont pull it off in vain?

IH8URDSM: you have truly proven yourself as a self-righteous jackass today. In trying to insult my "grammer" you managed to spell it wrong, my son. It's g-r-a-m-m-a-r, perhaps you ought to go back to "grammer" school

SLW240: thanks for the help, someday perhaps I'll be knowledgeable enough to know about "engine dynamics" Golly, you must really know your stuff!