Well i actually looked at my heater core today and no leaks, or any other external leaks. I installed the mech gauge as well, gets to about 205 and sets steady, however there is still no pressure in system? What is the proper way to bleed these cooling systems? At work i usually use this funnel type kit which purges air out which is similar to just filling the radiator and lettin run but with less mess. Is there anything special about these cars? everything was good just prior to the other day. As of right now i have no signs of bhg still. Oil good plugs look good, car not overheating (no temp spikes or expansion overflow) I am i really looking into this way too much?
bhg or bad rad cap?
- Thread starter 89supra7mgte
- Start date
I have a Matco funnel for convience. There is nothing special you need to do. Others prop up the front of the car to get the air out. Do you not have a pressure tester? Or you do, and that is why you say you can not build pressure. If you do not build pressure, maybe the problem is the adapter piece.
I have not used the funnel yet gonna get it tomorrow while at work along with psi tester and compression tester. I say i have no pressure cause after running the for 20-30 min hoses still easily squeezable and can remove cap with no spray. (not safe i know) Can see coolant flowing as well. Have not pulled t-stat but might take a look at it tomorrow.
Still having issues. Please help. Used funnel and purged system, filled ex tank to proper level. Have pressure in system now, but tank is still filling to about an inch under lid, but not spilling out? Gauge is working now temp is only around 205 verified, have an occasional spike to 220 then drops right back down. Have noticed that when tank fills up and car cools off i can see the rows inside, coolant level drops. I still have no leaks and no signs of bhg. what am i doing wrong? Too much coolant? should i re purge and leave expansion tank empty? Tonight i am going to get another rad cap and new t-stat. But if there is something else i am missing please let me know.
You keep making this way more complicated than it needs to be. What exactly is the current problem?
Btw all this talk about air in the system cracks me up. It wasn't that long ago cooling systems *had* to run air in them. They never had problems nor does it makes sense they would.
Btw all this talk about air in the system cracks me up. It wasn't that long ago cooling systems *had* to run air in them. They never had problems nor does it makes sense they would.
Ok current problem is gauge spike. I presume it's the t stat opening. And the fact the Rad is always low never sucking out of the tank
When does it spike? On which side of the t-stat housing is the sending unit?
If coolant isn't being returned to the radiator the overflow path isn't airtight or the upper seal on the cap is leaking. Or there's something wrong with the vacuum valve in the cap. Is it the weighted or spring loaded type? Since you mentioned not making pressure I'm assuming it's the weighted type.
If coolant isn't being returned to the radiator the overflow path isn't airtight or the upper seal on the cap is leaking. Or there's something wrong with the vacuum valve in the cap. Is it the weighted or spring loaded type? Since you mentioned not making pressure I'm assuming it's the weighted type.
The cap is spring ill check return system and see if its sealed right. The location of the sender is Rad side of tstat which is probably my spike issue
Update on not so big problem. New t stat and rad cap again. Was doing some inspecting on rad and found that the lock tabs were bent inwards so cap would not completely seal probably making for release of coolant but not suction. Thanks jetjock. The tstat installed is a 185 so with funnel installed and watching gauge i can see that it is opening and pulling coolant in. went through 3 or 4 cycles of t stat and everything seems to be ok at this point. Not sure if too cool of coolant will have an affect on engine performance or not but the max temp at idle was 185 and cools down to 165-170 when fans are on. should i raise the fan cycle temp or be fine where i am at? the summer temps range from 80-100 and i will not be driving car in winter.
As mentioned it may take a day or two for any air in the system to be purge and the tank level to stabilize. Once it does you can adjust it to the proper level. I ran mine a couple of inches above the Full line. I'll again point out the system is designed to remain sealed and coolant added via the reservoir. The rad cap should not be removed any more than necessary.
Coolant temp should not be below 185-200 degrees. Not only is the engine more efficient at those temps but the ECU can enter the warm up enrichment and cold idle prescriptions if coolant temp falls to not much below that. Besides, what do you think your thermostat is doing when your fans push coolant temp below its setpoint?
Coolant temp should not be below 185-200 degrees. Not only is the engine more efficient at those temps but the ECU can enter the warm up enrichment and cold idle prescriptions if coolant temp falls to not much below that. Besides, what do you think your thermostat is doing when your fans push coolant temp below its setpoint?
Very true good point didn't think much the enrichment. Ill adjust my fans again tomorrow and see how that goes. I want it to run right around 195
Ok well got car to run at 195 running great found the answer to all my coolant questions BHG, unless for some other reason i get steam out of exhaust and a 3 foot fire hose blast out of rad when cranking? LOL. Getting ready for teardown Think i am gonna have my old block and head machined for mhg and use my internals off this engine. Would that be a good idea? Is there any other alternative to mhg. My car ran great had good tune and wasnt in constant boost could it be possible to just have not had the gasket seated properly, oe style. Soon as i get teh head off i think i will know more. Just need a little insight cant afford to have months of down time to have this engine torn all the way down and then sent out. thanks.
Comp test results tomorrow.
Comp test results tomorrow.
Most of the time the weakness in a mhg is the machining that is done. Did the shop who did the work know it was being machined for a mhg and do they even know what needs to be done to machine for a mhg. There are a lot of shops that will say sure we can machine for a mhg and then do a normal machine job, this is not good enough for a mhg.
The best places I have found strangely enough for the best and cheepest machine work are actually boat engine shops. I got my block decked and honed, the head shaved and both cleaned, and the crank lightened balanced and knife edged all for $150, hell they will titanium sleeve the motor for $150 per cyl including sleeves and all. The normal automotive machine shops wanted $300+ just to deck the block and shave the head, and they wanted around $800 to replace the valve seals with the valves in the head or $600 to do them with the valves out. And most of them told me there is no difference in machining for a mhg and a normal gasket and told me I should stay away from mhgs because they are not as good as composite gaskets.
The best places I have found strangely enough for the best and cheepest machine work are actually boat engine shops. I got my block decked and honed, the head shaved and both cleaned, and the crank lightened balanced and knife edged all for $150, hell they will titanium sleeve the motor for $150 per cyl including sleeves and all. The normal automotive machine shops wanted $300+ just to deck the block and shave the head, and they wanted around $800 to replace the valve seals with the valves in the head or $600 to do them with the valves out. And most of them told me there is no difference in machining for a mhg and a normal gasket and told me I should stay away from mhgs because they are not as good as composite gaskets.
I do not know where the po had the block and head done at but i do know everything was correct. Back plate was machined on block. All had mirror finish to it. But being i didnt know the condition prior i put a new gasket on anyways, composite. I have 300 total miles on the jdm engine. I am putting another composite on but of better quality. I can not afford to tear the engine out and down to install an mhg.
You know i am not too sure on the mhg i would like to put it on and go with it. the engine probably has 300 miles on since i bought it. Looking at the old mhg looks like they might have done factory torque on it thus maybe causing a leak. There are no signs of it leaking i just didnt want to risk it at the time you know. I know its not proper but given the head and block were done proper for the mhg what are the chances of reusing the gasket on the block?
what brand is the mhg? should be able to reuse.
maybe it simply wasnt torqued enough
ARPs is ~85ft/lb with moly lube, or 103 with 30wt oil.
stock bolts are good to 74 before entering plastic region, courtesy of reg reimer's research.
remove the factory coating on the mhg with acetone and recoat with copper spray, your good to go.
maybe it simply wasnt torqued enough
ARPs is ~85ft/lb with moly lube, or 103 with 30wt oil.
stock bolts are good to 74 before entering plastic region, courtesy of reg reimer's research.
remove the factory coating on the mhg with acetone and recoat with copper spray, your good to go.
Ok what about machine work? Do you think the 300 miles I put on will affect anything? I have the head studs also.
For MHG, take a good aluminum 24in+ level with machined facing and do the TSRM procedure[http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=EM&P=42] to check square.
By the time your temp gauge tells you something is wrong, you've already super heated the breached areas, chancing an uneven surface.
Composite gaskets are more lenient and don't need a "perfect" surface, the route to take if you decide you don't need to boost hehe
Cut to the chase and strip the head down enough for the machine shop to skim it again, don't "save" time now and leave it up to question in the future.
By the time your temp gauge tells you something is wrong, you've already super heated the breached areas, chancing an uneven surface.
Composite gaskets are more lenient and don't need a "perfect" surface, the route to take if you decide you don't need to boost hehe
Cut to the chase and strip the head down enough for the machine shop to skim it again, don't "save" time now and leave it up to question in the future.
Ok now the gauge went to 230 for just a few seconds before i stopped and shut it down. I will check for square and flatness per tsrm, but do you think that 230 is enough to warp or change the flatness of the head? Its not so much about saving time as it is not having the funds available for the proper resurface of head and block. soon as i get the head off ill know for sure what i am working with. Might just go back to composite? Talked to a toyota tech that knows his shit on the 7m he said with a proper hg install and prep with proper tq you should be able to manage 450hp out of it. and an occasional 18psi here and there. Said the longevity of gasket might be shorter when running 18psi. I am still in the middle of what to do.