88 Mr2 overheating problems!! help me!!!

mr2kydd1790 · 09-22-2009, 11:50 AM

i had an 87 mr2 n/a then sold it for a sc 88 mr2. before i sold my 87 i was having overheating problems. it would be fine till i drove it down the freeway for a period of time then it would overheat. i fixed the thermostat, water pump, radiator cap, and head gasket. but it still overheated. then i sold it and got the sc model. i bought it drove it about 40 miles doing 60 and bam overheated just like the 87. i can drive the 88 all day as long as i am going 50 or less and it doesnt spike. not sure wat it is. maybe my radiator. it also leaks around the thermostat housing only when running high pressure. have no clue wats up. maybe radiator??? idk its the only thing i did not fix on my 87.

randomxzero · 09-22-2009, 12:49 PM

fix the leak it could be getting air through that leak...
also did you purge the system? on the 87?

mr2kydd1790 · 09-22-2009, 04:01 PM

i did not purge the system. i did it on the 88 though. i cant pin point the leak exactly when i am crusing on the free way and i get done. the top of my transaxle has antifreeze pooled up on it right below the thermostat housing but you can also see where it sprays all the way towards the battery and on the side of the engine bay. idk if it is the housing or if it is a hose. havent been able to dig in deep. but did change the thermostat already.

randomxzero · 09-22-2009, 04:24 PM

fix the leak purge the system again and still see if its casuing it..

lsgheero · 09-22-2009, 04:42 PM

Quote:

Originally Posted by mr2kydd1790

i did not purge the system. i did it on the 88 though. i cant pin point the leak exactly when i am crusing on the free way and i get done. the top of my transaxle has antifreeze pooled up on it right below the thermostat housing but you can also see where it sprays all the way towards the battery and on the side of the engine bay. idk if it is the housing or if it is a hose. havent been able to dig in deep. but did change the thermostat already.

My recommendation.... is that if you cannot locate the leak have someone help you and either your or them rev the engine increasing it little by little until you see the source of the leak since by your description it seems to only show under extreme pressure/volume.

With the car parked and in neutral lol

mr2kydd1790 · 09-22-2009, 06:29 PM

also. when i changed the thermostat out and flushed and bled the system. i went to drain the radiator and nothing came out. i took a piece of aviation saftey wire and put it in the drain. soon after, anti freeze came out with a lot of sand in the radiator. i was thinking that it may be overheating at high rpm because the system may be clogged and not sufficiantly cooling it. and i can drive all day in low rpms wit less need for the cooling wit out it overheating.

dirocyn · 09-22-2009, 08:32 PM

Sand in the radiator is bad news, not sure how it would get in there unless the system was open for a long time. I suggest you pull the radiator hoses and flush the whole system out with a garden hose until the water comes out in a clean, steady stream. Might be a good time to replace some hoses, too.

If you're replacing other parts/hoses around the thermostat housing (to fix your leak) you could run the hose through there too. I'd verify the leak is fixed and all hoses are on securely before draining to refill with a proper mix of antifreeze.

mr2_jake · 09-23-2009, 11:21 AM

You can't just wash away a clogged radiator. Pull it out and take it to a reputable radiator shop. I see this happen on a daily basis at work... A small leak should not cause overheating, that is as long as the system is kept full. A plugged radiator however WILL cause overheating only at higher speeds/rpm

shin · 09-29-2009, 10:14 AM

if the radiator is clogged i wouldnt even worry about taking it to a radiator shop to get it cleaned.. it will probably cost more then a new one... new ones are only 95 from the zone.. AutoZone.com | | Radiator | RADIATOR

dirocyn · 09-30-2009, 10:50 AM

Quote:

Originally Posted by mr2_jake

You can't just wash away a clogged radiator.

I beg to differ. I got great loads (easily over 2 cups) of sediment out of the radiator in my Chevy truck earlier this summer. Now, it wasn't completely clogged and I ran probably 100 gallons through it--with the radiator out, and shifting the angle around so the water could reach all the various internal passages. A radiator is just plumbing, whether you can remove a clog depends on where it's clogged and what it's clogged with. It's worth a try, especially if you're on a budget. If you can get it to flush clean, you don't have to buy a radiator. If you can't, what have you lost? An hour and a half of time, dry shoes, and maybe a dollar's worth of water. If I tried that and couldn't get a blockage out, I might try filling the radiator with water and CLR and letting it soak for a couple of days to dissolve calcium, lime, and rust deposits. Yes, it might screw up the radiator--but the radiator's already screwed up, right?

mr2_jake · 09-30-2009, 12:21 PM

You may get all the loose deposits, but trust me, you can't get it completely clean. I work at a little shop called Riverside Repair..& RADIATOR! That's what we do. I see this sort of thing happen all the time! Sure, you can "flush" it yourself, and get a good load of s*** out of it, but that doesn't mean it is spotless. Even our Wynn's coolant flush machine can't get 'em perfect, just "pretty clean". If you popped the end-tanks off any old radiator, sure you could flush plenty of crud out, but there are deposits that WILL NOT come loose with just running water. CLR is not a bad idea. I can't see this harming the radiator any. If you want to be 100% sure the radiator is clean, it needs to be disassembled and rod out. Don't mean to be a pessimist, but I'm just letting you know what years of experience has taught me!

jsnod25 · 10-01-2009, 08:23 AM

also, to touch on the leak around the tstat. If you replaced it, did you put new gaskets on? and any hoses that you took off, did you replace with new ones? or are there clamps on the connecting points? Rubber looses its elasticity, and if you take it off and try to put it back on, you could easily loose your seal. I would back track to whatever parts youve replaced and check the connecting hoses and whatnot. If they go on and off easily then you have a problem. They can also dry out and crack too.

Radiator is a big issue, but even with a new radiator, antifreeze squirting everywhere will cause other big issues, that stuff will take the paint off your car if not cleaned off right away.

mr2kydd1790 · 10-05-2009, 03:22 AM

thanks for all the help guys. as for the leak. yes i did replace the seal and put some rubber sealent around it for extra help. what it did notice though when i had the housin out their was a slight dent on the inside of the housing where the seal fits. it did not look big enough to cause a problem but not sure. and as for the hoses. i noticed the previous owner replaced alot of the hoses and clamps. which could have been where the sand had entered. also the lazy a** left all the stock clamps on the hoses but just simply pushed them down the hoses. not exactly sure why but whatever they dont seem to be bothering the hoses except for the main, bigger one going into the tstat. i am kind of thinking that could be the problem too. because the pressure in the hoses the their has formed a bit of a bulge on the hose from where the old clamp that has been pushed down about 4 inches to the new clamp at the end of the hose clamped down to the housing. i thought maybe because the hose is under pressure from the old clamp it could have cracked it between the new clamp and the old one due to stress. i havent messed with it really because its stored for the winter time. damn minnesota weather keeping me from driving my mr2!!. im thinking on saving some cash and replacing the radiator and triyng to flush the whole system. because their was sand in the radiator i figure theirs sand in the hoses going back to the motor as well. if you have any tips on how to clean the system out to keep my new radiator from cloging again that would be very helpfull. also when i have time to get back to the cities i will try to take some pics and figure out how to put them on here to show what the hoses look like. i still have not had time to completly pinpoint where the antifreeze is spraying from. i was thinking on letting the car get to temp and have someone hold it at high rpm to see if i can see where the antifreeze is spraying. if you have any better ideas on how to find the leak let me kno.

Pilot · 10-05-2009, 11:43 PM

Take it to a facility that has radiator flushing equipment that allows you to see what is pumped in and what flushes out of the system, they can pump about 5 gallons of fresh coolant through the system and clean everything out much better that you will ever do yourself. It cost me 87.00 and was worth it after I saw the stuff that came out.

09-22-2009, 11:50 AM	#1 (permalink)
mr2kydd1790 No Skills Join Date: Sep 2009 Location: minnesota Posts: 10 Thanks: 4 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	88 Mr2 overheating problems!! help me!!! i had an 87 mr2 n/a then sold it for a sc 88 mr2. before i sold my 87 i was having overheating problems. it would be fine till i drove it down the freeway for a period of time then it would overheat. i fixed the thermostat, water pump, radiator cap, and head gasket. but it still overheated. then i sold it and got the sc model. i bought it drove it about 40 miles doing 60 and bam overheated just like the 87. i can drive the 88 all day as long as i am going 50 or less and it doesnt spike. not sure wat it is. maybe my radiator. it also leaks around the thermostat housing only when running high pressure. have no clue wats up. maybe radiator??? idk its the only thing i did not fix on my 87.

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09-22-2009, 12:49 PM	#2 (permalink)
randomxzero Downshift to Reverse! Join Date: Sep 2008 Location: 562 Posts: 1,032 Thanks: 10 Thanked 5 Times in 5 Posts iTrader Rating: (0/0% )	fix the leak it could be getting air through that leak... also did you purge the system? on the 87?

09-22-2009, 04:01 PM	#3 (permalink)
mr2kydd1790 No Skills Join Date: Sep 2009 Location: minnesota Posts: 10 Thanks: 4 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	i did not purge the system. i did it on the 88 though. i cant pin point the leak exactly when i am crusing on the free way and i get done. the top of my transaxle has antifreeze pooled up on it right below the thermostat housing but you can also see where it sprays all the way towards the battery and on the side of the engine bay. idk if it is the housing or if it is a hose. havent been able to dig in deep. but did change the thermostat already.

09-22-2009, 04:24 PM	#4 (permalink)
randomxzero Downshift to Reverse! Join Date: Sep 2008 Location: 562 Posts: 1,032 Thanks: 10 Thanked 5 Times in 5 Posts iTrader Rating: (0/0% )	fix the leak purge the system again and still see if its casuing it..

09-22-2009, 06:29 PM	#6 (permalink)
mr2kydd1790 No Skills Join Date: Sep 2009 Location: minnesota Posts: 10 Thanks: 4 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	also. when i changed the thermostat out and flushed and bled the system. i went to drain the radiator and nothing came out. i took a piece of aviation saftey wire and put it in the drain. soon after, anti freeze came out with a lot of sand in the radiator. i was thinking that it may be overheating at high rpm because the system may be clogged and not sufficiantly cooling it. and i can drive all day in low rpms wit less need for the cooling wit out it overheating.

09-22-2009, 08:32 PM	#7 (permalink)
dirocyn Cage Fighter Join Date: Mar 2009 Posts: 133 Thanks: 6 Thanked 12 Times in 12 Posts iTrader Rating: (0/0% )	Sand in the radiator is bad news, not sure how it would get in there unless the system was open for a long time. I suggest you pull the radiator hoses and flush the whole system out with a garden hose until the water comes out in a clean, steady stream. Might be a good time to replace some hoses, too. If you're replacing other parts/hoses around the thermostat housing (to fix your leak) you could run the hose through there too. I'd verify the leak is fixed and all hoses are on securely before draining to refill with a proper mix of antifreeze.

09-23-2009, 11:21 AM	#8 (permalink)
mr2_jake Many skills... Join Date: Sep 2009 Location: Billings, MT Posts: 83 Thanks: 0 Thanked 7 Times in 7 Posts iTrader Rating: (0/0% )	You can't just wash away a clogged radiator. Pull it out and take it to a reputable radiator shop. I see this happen on a daily basis at work... A small leak should not cause overheating, that is as long as the system is kept full. A plugged radiator however WILL cause overheating only at higher speeds/rpm

09-29-2009, 10:14 AM	#9 (permalink)
shin MR2 WINS Join Date: Jul 2009 Location: appleton,wi Posts: 3 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	if the radiator is clogged i wouldnt even worry about taking it to a radiator shop to get it cleaned.. it will probably cost more then a new one... new ones are only 95 from the zone.. AutoZone.com \| \| Radiator \| RADIATOR

09-30-2009, 12:21 PM	#11 (permalink)
mr2_jake Many skills... Join Date: Sep 2009 Location: Billings, MT Posts: 83 Thanks: 0 Thanked 7 Times in 7 Posts iTrader Rating: (0/0% )	You may get all the loose deposits, but trust me, you can't get it completely clean. I work at a little shop called Riverside Repair..& RADIATOR! That's what we do. I see this sort of thing happen all the time! Sure, you can "flush" it yourself, and get a good load of s*** out of it, but that doesn't mean it is spotless. Even our Wynn's coolant flush machine can't get 'em perfect, just "pretty clean". If you popped the end-tanks off any old radiator, sure you could flush plenty of crud out, but there are deposits that WILL NOT come loose with just running water. CLR is not a bad idea. I can't see this harming the radiator any. If you want to be 100% sure the radiator is clean, it needs to be disassembled and rod out. Don't mean to be a pessimist, but I'm just letting you know what years of experience has taught me!

10-01-2009, 08:23 AM	#12 (permalink)
jsnod25 How did this get changed? Join Date: Sep 2009 Location: Va beach, va Posts: 128 Thanks: 6 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	also, to touch on the leak around the tstat. If you replaced it, did you put new gaskets on? and any hoses that you took off, did you replace with new ones? or are there clamps on the connecting points? Rubber looses its elasticity, and if you take it off and try to put it back on, you could easily loose your seal. I would back track to whatever parts youve replaced and check the connecting hoses and whatnot. If they go on and off easily then you have a problem. They can also dry out and crack too. Radiator is a big issue, but even with a new radiator, antifreeze squirting everywhere will cause other big issues, that stuff will take the paint off your car if not cleaned off right away.

10-05-2009, 03:22 AM	#13 (permalink)
mr2kydd1790 No Skills Join Date: Sep 2009 Location: minnesota Posts: 10 Thanks: 4 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	thanks for all the help guys. as for the leak. yes i did replace the seal and put some rubber sealent around it for extra help. what it did notice though when i had the housin out their was a slight dent on the inside of the housing where the seal fits. it did not look big enough to cause a problem but not sure. and as for the hoses. i noticed the previous owner replaced alot of the hoses and clamps. which could have been where the sand had entered. also the lazy a** left all the stock clamps on the hoses but just simply pushed them down the hoses. not exactly sure why but whatever they dont seem to be bothering the hoses except for the main, bigger one going into the tstat. i am kind of thinking that could be the problem too. because the pressure in the hoses the their has formed a bit of a bulge on the hose from where the old clamp that has been pushed down about 4 inches to the new clamp at the end of the hose clamped down to the housing. i thought maybe because the hose is under pressure from the old clamp it could have cracked it between the new clamp and the old one due to stress. i havent messed with it really because its stored for the winter time. damn minnesota weather keeping me from driving my mr2!!. im thinking on saving some cash and replacing the radiator and triyng to flush the whole system. because their was sand in the radiator i figure theirs sand in the hoses going back to the motor as well. if you have any tips on how to clean the system out to keep my new radiator from cloging again that would be very helpfull. also when i have time to get back to the cities i will try to take some pics and figure out how to put them on here to show what the hoses look like. i still have not had time to completly pinpoint where the antifreeze is spraying from. i was thinking on letting the car get to temp and have someone hold it at high rpm to see if i can see where the antifreeze is spraying. if you have any better ideas on how to find the leak let me kno.

10-05-2009, 11:43 PM	#14 (permalink)
Pilot Master MotorcycleMechanic Join Date: Oct 2009 Posts: 74 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	Take it to a facility that has radiator flushing equipment that allows you to see what is pumped in and what flushes out of the system, they can pump about 5 gallons of fresh coolant through the system and clean everything out much better that you will ever do yourself. It cost me 87.00 and was worth it after I saw the stuff that came out.