After reading many accounts of erratic coolant temperatures, questioning sensors, ECU, temp gauge,etc, I did this:
I removed the thermostat from the bottom of the engine where it lives. For some reason Suzuki decided to put it there instead of where everybody else puts it, (up top). So what. I removed it and buttoned it up. Then I took 2 thermostat housings from, I think, about a mid-'80s Chevy Cavalier or something like that, it does not matter what, just take 2 housings and bolt them together with a thermostat inside, cut the big upper hose in two, and insert this assembly. I drilled a 1/8 inch hole in the thermostat disc before assembly, and made sure the pellet faces the motor. Absolutely the END of erratic coolant temps, and all the problem that go with it. 2 years in, 25,000 miles no more coolant problems. I have never seen this fix before, comments and questions welcome. Hole size in disc was critical. Mechanical fan was replaced by electric fan, triggered by Honda Accord thermo switch installed in lower hose.-Dan Strayer
[quote='fixkick' pid='3735' dateline='1427596194']
the small tube behind the thermostat, if that pipe, does not flow at all times, the thermostat fails on j18 or J20 engines.
its a very very odd design this method. (same with heater core blocked,) if the core blocks then the bypass line must not be blocked, or bam.
thermostat, goes nuts.
I don't think that pipe is totally clogged, heater still works....I could not make the coolant temp steady, it would over cool going down a long grade. Moving the thermostat to the top hose solved all problems. Thanks for your reply!
(03-30-2015, 07:43 AM)fixkick Wrote: thanks for sharing, i do love home brew fixes, sure do !
is it cold out,? i didnt know it s was frigid engine, that is totally different.
how cold out is it, here is 80f so , ive no clues.
the thermostat has a rubber surround ring, and seen many wrong (100s of emails) with it missing or using a paper gasket instead.
doing so floats the thermostat, it just leaks bad. (goes nuts)
this causes thermostat floa.
nor a backwards stat. (both hopeless cases)
they do use this engine in many cars, J18/20 and not one does this , set up right. non do. 50,000 car or more.....
j20 is just a stroked 1.8.
Frigid 2:
the front fan clutch can seize and on cold days, the engine will go frigid, up in Montana or Canada or Alaska, up there they block 1/2 the RAD with cardboard, to Solve this issues. -50F is bad news.
did the engine temperature surge? up and down, if yes, that is the STAT wax pellet going nuts, (due to lack of flow via bypass and or tube 22.)
remember pipe 22 can kill both paths, if necked down its a big problem on this car.
the stat air bleed not sitting on top , invites, air pockets and thermostat will not run in air. ever. nor will the ECT at rear of head.
the symptoms are surge. hot/cold,hot, repeat. with air or lack pipe 22 flow, full normal flow.
I checked the air bleed position...it was up. New thermostat...Gasket, proper one. Engine temp was still erratic, was never run below 10 or 15 degrees f but up to high 90s in summer prior. Now any ambient temp is fine. I normally am in Idaho.
Symptoms were very slow warm-up, (so the 8 miles to town in chilly weather was open loop all the way)... engine temp sometimes surged but mostly would not maintain operating temp, so closed loop was hard to attain, just generally erratic. I concluded that tube 22 was the culprit, but resistances on ECT were right, and heater works fine. Any other motor I ever saw had the thermostat up top , right before big hose to top of radiator so I put it there. MPG went from low 20s to 29 at 60-64 MPH. Temp gauge is now half way up at all times,rock steady, Accord thermo switch closes at 180f, electric fan from unknown vehicle.
I put an older brass radiator in it as OEM was damaged, much better in hot weather (today I was in heavy traffic in Tucson, 93f, impossible to make it overheat.), but does like 1/2 cardboard below about freezing. I could send photo. Tube 22 was not directing sufficient coolant to wax pellet, that's all I could conclude. Thanks.
this engine runs a unique thermostat. too. so if that was wrong.....
many stores sell you the wrong stat. the best way to get the correct one is to buy and Esteem 1.8L stat, if they dont know what 1.8L means , RUN !
see some choices here, for engine code 2, (VIN) buy a thermostat that matches ENGINE, 2 not 0. http://www.fixkick.com/buy-parts.html#STAT18
Here it is , the very unique system (unlike any G16) note how the flow is backwards from G16 engine, making a G16 thermostat useless.... and many stores sell the wrong stat, show me the makers partnumber and i can look it up, easy.
all stores sell the correct thermostat. and it will correct your cars failure, im sure. you have the wrong thermostat. (did)
you are not the first to get it wrong. (they stacked the deck on you.)
04-01-2015, 03:30 AM (This post was last modified: 04-01-2015, 03:56 AM by fixkick.)
it is special and operates 180 degree flows from G16.
sure mpg gets better with a cold engine all the time, its in ECU warm up mode, sucking fuel like crazy, 180F temps are first, in EFI. always first.
and not take a day getting to 180g and not surging.
no lie the cooling is counterproductive . and fits many suzuki cars,not just RWD.
if the pipe 22 is packed the wax pellet never gets hot waterflow.
so the wax never gets hot, and never opens. so the valve is closed, there is no radiator flow now.
then lets say by pure luck or conductive heat from block to pump the wax warms a bit and expands, then the stat opens a bit, OOPS the water out of the RAD is cold now. (say your moving fast too, and its real cold out, (makes this more clear using worst cases )
and rad water lands on same wax pellet and the thermostat slams shut (BAM), and repeats over and over.
no G16 works like this. the G16 has water flowing in the intake gallery all the time, the J18 has no such place.
this is pure, J18/j20 and j24 action here.
i'd buy a real thermostat , by name and correct number. id not use something from autozoned, ever. no Dura-stuff.
if that didnt fix it. i'd.
and then back flush 22 . all paths there, even the iAC thermal air valve (idle) needs to work right.
i do hope is not clogs,
as an aside to that, the tube 22 keeps the thermostat at the head water temperature at all times, even when, the RAD is ice brick cold.
then as the STAT lets in some of that cold water,it mixes with the hot , and the stat closes just a tiny bit, to hold 180f.
if the 22 pipe is clogged all hope is gone. its 100% used at all times.
the thermostat is tuned to the character of the flow in pipe 22, and is different than the G16.
(04-01-2015, 03:30 AM)fixkick Wrote: it is special and operates 180 degree flows from G16.
sure mpg gets better with a cold engine all the time, its in ECU warm up mode, sucking fuel like crazy, 180F temps are first, in EFI. always first.
and not take a day getting to 180g and not surging.
no lie the cooling is counterproductive . and fits many suzuki cars,not just RWD.
if the pipe 22 is packed the wax pellet never gets hot waterflow.
so the wax never gets hot, and never opens. so the valve is closed, there is no radiator flow now.
then lets say by pure luck or conductive heat from block to pump the wax warms a bit and expands, then the stat opens a bit, OOPS the water out of the RAD is cold now. (say your moving fast too, and its real cold out, (makes this more clear using worst cases )
and rad water lands on same wax pellet and the thermostat slams shut (BAM), and repeats over and over.
no G16 works like this. the G16 has water flowing in the intake gallery all the time, the J18 has no such place.
this is pure, J18/j20 and j24 action here.
i'd buy a real thermostat , by name and correct number. id not use something from autozoned, ever. no Dura-stuff.
if that didnt fix it. i'd.
and then back flush 22 . all paths there, even the iAC thermal air valve (idle) needs to work right.
i do hope is not clogs,
as an aside to that, the tube 22 keeps the thermostat at the head water temperature at all times, even when, the RAD is ice brick cold.
then as the STAT lets in some of that cold water,it mixes with the hot , and the stat closes just a tiny bit, to hold 180f.
if the 22 pipe is clogged all hope is gone. its 100% used at all times.
the thermostat is tuned to the character of the flow in pipe 22, and is different than the G16.
Is the fact that the heater still woks well, evidence that tube 22 is not clogged? By the diagram, looks like there would be no exit for water from heater core if that tube was clogged. Also, ECT sensor specs were good throughout cold to warm range. How could that be w/ clogged 22?
04-01-2015, 05:59 AM (This post was last modified: 04-01-2015, 06:00 AM by fixkick.)
seems so. if that tube is 100% packed it will kill all cab heat.
the ECT is submerged in the head rear housing, the hottest spot if loop. is really exposed to the head rear water jackets directly, what matter is the water at thermostat. it self.
the G16 stat opens and really hot water exits the thermostat valve..
the J18 opens and cold water rushes in, THIS IS A BIG DIFFERENCE here. (design wise)
that is why im so onto wrong thermostat,
but for sure ive no idea what is wrong with your actual car, only the possibles.
![[Image: 18Lhorror.jpg]](http://www.fixkick.com/Cooling-engine/18Lhorror.jpg)