Jilly Posted March 10, 2006 Share Posted March 10, 2006 Hi. I recently bought an 89 Sub wagon, 1.8 FI Turbo. Both head gaskets were blown on purchase. Fixed that and got it running but it overheated still. The last owner apparently thought 5-6 cans of stop-leak would fix the heads! I think I've successfully flushed the block, finally, but it's still getting hotter than I like. Temp guage goes up to about 3/4 after 40 miles of highway driving. The oil pressure starts out around 45 psi but drops down to about 20 psi once it warms up. I put on a new sender unit to make sure it was an accurate reading. It hasn't actually overheated since the persistent cooling system flushes, but it gets hot enough to hit the overflow tank. Is this within normal parameters or should I start looking at the oil pump? Maybe an engine flush? Thanks for any input! Link to comment Share on other sites More sharing options...
Dylan86GL10 Posted March 10, 2006 Share Posted March 10, 2006 How many miles does the motor have? The pump gasket usually goes first which allows internal pressure to bypass the motor. Link to comment Share on other sites More sharing options...
Jilly Posted March 10, 2006 Author Share Posted March 10, 2006 127,000 barely breaking in a Sub. Link to comment Share on other sites More sharing options...
rllywgn Posted March 10, 2006 Share Posted March 10, 2006 i had an 87 turbo wagon down in arizona and it basically always sat at 2/3 to 3/4 on the temp gauge, and this was after replacing both heads and throwing on a new water pump and 2 row radiator. if you dont have one yet, try an aftermarket temp gauge. equus has a temp gauge thats rather cheap and has the correct adaptor in the package already. Wally mart has it... 10 bucks.. that should give you an actual temp to work with... my car always sits at 190 on the freeway up here in washington.. but i consistently had readings around 210 down there and that was pretty normal... a/c seemed like a no-no at anything above 50mph though... hope this helps rllywgn Link to comment Share on other sites More sharing options...
Holmes Posted March 10, 2006 Share Posted March 10, 2006 The radiator is most likely clogged if all that stop-leak was used. And flushing a clogged one is not gonna work to well in my experience. Link to comment Share on other sites More sharing options...
Jilly Posted March 10, 2006 Author Share Posted March 10, 2006 Thanks. Been thinking about aftermarket guages, just to be sure. Not knowing what caused the heads to blow has me a bit twitchy with the readings. Would rather not change the oil pump if I don't have to- expensive part from what I've seen and not an terribly easy job but I'm up for it if it needs it. I just finished the last radiator flush so I'm still on straight water until I'm sure it's clear. That'll raise the temp a bit, I know, but shouldn't be this much. Texas car- lower 90's today. A/C is on the list to fix, but not a priority yet. Link to comment Share on other sites More sharing options...
rllywgn Posted March 10, 2006 Share Posted March 10, 2006 if you do end up needing a radiator... check out www.radiatorbarn.com 140 bucks or less for a 2 row and free shipping I've purchased 5 radiators from them now (different cars) and service had always been very good... about 5 day wait on shipping typically rllywgn Link to comment Share on other sites More sharing options...
Jilly Posted March 10, 2006 Author Share Posted March 10, 2006 Could be the rad, still. Didn't see much sense in putting a new one on until I cleared the crap from the block. Are the oil pressure fluxuations normal, then? Never seen that big a gap in any other subs I've owned. Started driving on a 79 hatchback, btw. Great car! Flipped the odometer on that one several times before retiring it (still running). I miss carbs. Link to comment Share on other sites More sharing options...
rllywgn Posted March 10, 2006 Share Posted March 10, 2006 most ive had will be between 50 and 75psi on startup after warm it should sit at about 5-10psi at idle, and about 10psi for every 1000rpm when driving rllywgn Link to comment Share on other sites More sharing options...
Jilly Posted March 10, 2006 Author Share Posted March 10, 2006 So it's actually a little high at idle (20psi). That's good to know. Think having my rad routed would do it or just go for the new one? Link to comment Share on other sites More sharing options...
rllywgn Posted March 10, 2006 Share Posted March 10, 2006 i had a radiator in my supra "rodded" i think they said... whatever it is they do to clean it... it cost as much as a oem replacement radiator (300.00) after labor and what not... new radiator is just that... new... should be perfect right from the get go... imo rllywgn Link to comment Share on other sites More sharing options...
Jilly Posted March 10, 2006 Author Share Posted March 10, 2006 With a new one I wouldn't have to wonder... That's a good site you recommended, btw. At least changing the radiator is a whole lot easier than changing the oil pump. Bit by bit I'm getting this car running right! Funny, I move back to Texas and get the car I needed in the mountains (4wd)! Thanks for all the help, guys! I feel a lot better about the oil pump now. Link to comment Share on other sites More sharing options...
rllywgn Posted March 10, 2006 Share Posted March 10, 2006 i bought my wagon up here in washington then took it down to arizona as soon as i got the heads replaced... damn desert... no mud... i was also able to cool down a little more by modifying the front bumper for more airflow... this may seem a little extreme but cruising temps dropped a few degrees... this is about mid way through the process showing the actual bumper core modification (center cutout) the bumper cover is pretty easy to match the cut if you so desire... Im not saying do it... but yet another idea... rllywgn Link to comment Share on other sites More sharing options...
Jilly Posted March 10, 2006 Author Share Posted March 10, 2006 That's a good idea. More airflow Good. Hmm.. I'll bet I could make a scoop, come to think of it. New radiator first, then mods. Plenty of mud come monsoon season- at least there was in Tucson when I was there. No drainage. But who wants to get out when it's 120 degrees? Link to comment Share on other sites More sharing options...
Jilly Posted March 11, 2006 Author Share Posted March 11, 2006 Ok. Just to make sure we're on the same page: We've pretty much ruled out the oil pump and gotten down to the radiator. Starting my 40 mile test trek in stop and go traffic, the temp stayed a happy half way. After 20 minutes or so of 65-70 mph driving it started to get hotter (gradually) not long after the oil pressure dropped to around 20-25 psi. Wasn't really watching the rpms at that point. We're still thinking radiator, then? I'm pretty happy with the prognosis, but my roomy is still questioning it. Link to comment Share on other sites More sharing options...
seattlelegacy Posted March 11, 2006 Share Posted March 11, 2006 Personally, I'm not convinced with the radiator either. When you redid the heads, did you have them machined? Were the heads cracked, even a little tiny bit between the cylinders. Sometimes, those are tough to see, and if they were there, then you never really "fixed" the original problem those heads can warp... The reason all the stop leak was used was probably to keep the coolant in the cooling system when the headgaskets blew, but new stop leak folmulations aren't going to clog up a radiator - they would probably clog the cooling ports in the heads before they clog up a radiator. If it was the older stuff, maybe. I haven't looked at the specs on the cooling port size in the heads vs. the size of the tubing running through the radiator, but that's my guess. And sorry if it seems like a dumb thing to say, but your thermostat, radiator cap, and all those "simple" little things have been replaced? Link to comment Share on other sites More sharing options...
Jilly Posted March 11, 2006 Author Share Posted March 11, 2006 Replaced the thermostat with 180 degree one. Actually just installed one as there wasn't one when I bought the car. Guess he thought it didn't need one! Haven't replaced the cap, yet. Seems to be doing it's job, though- tight until hot enough to send fluid to the resevoir. Had the heads milled- found a place with the proper machine/experience for aluminum heads. Looked them over pretty thoroughly when they were out, didn't see any indication of cracking at all. Not getting any semblance of water in the oil anymore, either. Both the oil and water levels have remained constant, no leaks/drips. My oil cap isn't sealing correctly, that's next on the list to replace. Getting some oil blowing out of that, but I take it as a good sign on the pressure more than a problem. Would a loose oil cap make a big difference in pressure? Link to comment Share on other sites More sharing options...
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