Hey everyone! Any help would be much appreciated!!! I bought this 87 7mgte supra, and off the bat had the HG replaced. About a month later the car started idling rough for no reason. I gave it throttle and plumes of white smoke poured out of the exhaust. After a moment of driving, it cleared up until i came to a stop at a stoplight, and the problem happened again. I started pulling looking into the misfire, and found that coolant was pooling up in the #1 and #2 spark plug valley. started the car and let it run, but couldn't see any coolant seeping into the area. Drove it around the block and it had pooled up again. I tore the head off thinking the headgasket has to be blown somewhere for the coolant to be pouring out of the exhaust, the HG doesnt show any signs of failure. I thought a possible crack in the head, but after thorough c;leaning and inspection cant find one. Im pulling my hair out over this issue!!!! :aigo: Any help would be much appreciated! I will post some pics that may help?? Or possibly not, but couldnt hurt either way. Thanks supra community!!! :icon_bigg
Need help! Bhg issue??
- Thread starter TURBOTIMMY
- Start date
Thats what i thought at first, but couldn't find any loose hoses, especially that were in that area. Although i didnt check the plugs with the allen head to see if they were leaking.
Check your throttle body gasket. Replacing it's a real pain in the ass, but it's pretty cheap. I had to do this a few years back to fix a coolant leak. I actually paid someone to do it since I couldn't get my fat fingers around it, but it still cost less than $100. You can probably do it yourself for $10 or $15.
The TB gasket has nothing to do with sealing off coolant...the hoses leading to the TB and ISCV does though.
What kind of HG? Metal ones look fine even tho' they're leaking.
If the block was decked w/o the front cover it will fail the HG, too.
Blown TB gasket could be the culprit - but not many other things put coolant into the cylinders.
Look at the piston tops - if they're clean or wet it will tell u where the coolant's going. If it's only in some of the cylinders - prolly BHG. Compression test.......?
If the block was decked w/o the front cover it will fail the HG, too.
Blown TB gasket could be the culprit - but not many other things put coolant into the cylinders.
Look at the piston tops - if they're clean or wet it will tell u where the coolant's going. If it's only in some of the cylinders - prolly BHG. Compression test.......?
syty1;1308080 said:
No way the TB gasket is the cause.
You guys need to get your facts straight before posting in the Tech section :3d_frown:
It was a graphite gasket. I used that one as a temporary fix to get me through September(When i leave for basic training), but obviously it was extremely short term temporary. Once im back, the engine is getting a full build, no cut corners, NOTHIN! But even the graphite gasket looked okay, no real signs of failure. Is it common for the head to crack, or the block?? I appreciate all your guys' input!
Vs heading off on a "cracked head tangent", replace the hoses leading to the TB and ISCV. Look here: http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=CO&P=2
So far, the "input" given above is BS (with the exception of post #2). For coolant to get into the spark plug wells, it has to either come from a pressure source spraying coolant across the top of the motor or from the TB/ISCV lines. There are no coolant passages at the top of the head where the cams are...oil yes, coolant no.
So far, the "input" given above is BS (with the exception of post #2). For coolant to get into the spark plug wells, it has to either come from a pressure source spraying coolant across the top of the motor or from the TB/ISCV lines. There are no coolant passages at the top of the head where the cams are...oil yes, coolant no.
Could that also cause the rough idle, and coolant in the exhaust?? Or do you think these are separate problems??
TURBOTIMMY;1308099 said:
Coolant in your spark plug galley could definitely cause a rough idle, and missing in general. Fix your coolant leak.
If the HG was not installed properly...are you sure it's coolant in the exhaust? Is the coolant bottle overflowing and the car overheating?
To check for exhaust gas in the coolant, get a NAPA block tester.
Rough idle could be a number of things (including a BHG)...check the plugs and wires 1st.
To check for exhaust gas in the coolant, get a NAPA block tester.
Rough idle could be a number of things (including a BHG)...check the plugs and wires 1st.
Im psoitive its coolant in the ehx. Its white, and smells sweet like coolant. The coolant bottle is overflowing, which i guess right there, is telling me the head gasket is most likely blown.
gtsfirefighter
SM Expert on White trash
TURBOTIMMY;1308135 said:
Take the head to a machine shop and they can test it for leaks. Since you seemed the be worried about that the most, cross that off your list first. If it turns out fine, then have it machined and redo your HG. Coolant around the sparks plugs is still a mystery though, to me anyway.
I figured that would be my next step, i was just hoping someone would have some magical advice to remedy the problem. Off to the machinist i go! Hopefully it checks out fine, then putting it back together with a MHG. Thanks for your help guys, its always nice to have a second opinion!
gtsfirefighter
SM Expert on White trash
TURBOTIMMY;1308154 said:
Unless you're going to take the block and get it decked, don't waste your time with a MHG. Get a Toyota HG. If you're going to do a full rebuild after basic training, then go the MHG route.
If you use a MHG, you need to get the block decked in addition to the head. A MHG requires a very smooth surface to seal...otherwise it is high probibility you will be doing this again. For any HG, the block and head surfaces have to be flat...the TSRM shows the allowed warpage. Suggest you use ARP head studs (or bolts), torqued to ARP spec's.
This is true! I didnt even think about the block side of it. Toyota gasket it is! Thanks guys! Saved my arse once again!