So my Galant has had a few issues and I'm hoping that people here can give me a hand. The first issue was a coolant leak. The hose was replaced and coolant was put back in the car. The car had a super high idle until the coolant settled in again, so the idler screw was turned to lower the idle (it was extremely high, almost 4k). After the car settled out, the idle, which has always been 1200rpm or so, was set to 750, since that is where it should be at. The car immediately had some cooling issues, so idle was returned to 1200. After driving the car for a bit, it developed an issue and I do not build 20psi of boost as I normally do, the car now only builds 15psi. The idle is also erratic, varying between 1400 and 1800 rpms. When this issue first started, I simply drove the car for about an hour and was eventually able to build 20psi again. The next day (today), I am back to 15lbs. Does this sound like a boost leak or something related to the BISS screw? I feel like a vacuum line is kinked somewhere, but I'm not sure if there is a typical line that does this or the issue sounds like something different? Thanks for looking, hopefully I can resolve this.
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chrisfullwood
Well-known member
the idle surge seems to me like a boost/vacuum leak. why it would be affecting your cooling though is weird. because at idle, your radiator fan should move enough air to keep it cool. check all your hoses, make sure all the couplers are well connected, check all your little vacuum lines for pinholes, cracks, or cracks in any of the little plastic connectors.
if you don't see anything there, then i would suggest a new biss o-ring, and possibly looking at your throttle body as a potential source for the issue. did you hook it up to a logging device to see what it tells you that might be of help.
if you don't see anything there, then i would suggest a new biss o-ring, and possibly looking at your throttle body as a potential source for the issue. did you hook it up to a logging device to see what it tells you that might be of help.
When I had my idle set at 750 the car would get hot until I got on the gas a bit, then it would be fine. Possible that's a separate issue from the boost leak then? Also, that issue was solved by putting the idle back to 1200.
Last edited by a moderator:
AnotherNewb
Well-known member
+1 on doing a boost leak test. Something else I would suggest is a coolant pressure test to rule out a possible failing head gasket. Air in the coolant system will cause erradic over heating.
vr4hotness
Well-known member
most likly a boost leak...
DR1665
Well-known member
If you set base idle correctly (grounding out the ISC, all accessories off, engine/coolant at operating temp), and it still acts up, you might be looking at a failing ISC, a vacuum ("boost") leak, or some kind of tuning issue. Your mention of running 20psi suggests you have some mods installed, so it's possible something isn't tuned right.
If you've got cooling and idle issues, you really shouldn't be trying to force your way past them to 20psi. That's a recipe for disaster, imo. Double check your coolant level, make sure you "burp" the system to get the air out, and consider doing a compression test to get a bead on that headgasket.
Good luck.
If you've got cooling and idle issues, you really shouldn't be trying to force your way past them to 20psi. That's a recipe for disaster, imo. Double check your coolant level, make sure you "burp" the system to get the air out, and consider doing a compression test to get a bead on that headgasket.
Good luck.
GSX_TC
Well-known member
Quoting AnotherNewb:
Air in the coolant system will cause erradic over heating.
Hell yeah it will! Even with no leaks and no thermostat with two fans and a fluidyne, it'll get hot within ten minutes
Air in the coolant system will cause erradic over heating.
Hell yeah it will! Even with no leaks and no thermostat with two fans and a fluidyne, it'll get hot within ten minutes
Its an evoIII 16g, all hard ic pipe, 560cc injectors
Kinda modded...lol
I think the leak is a failing worm clamp. Picking up some tbolt clamps in the AM and I'll get back to everyone here.
Kinda modded...lol
I think the leak is a failing worm clamp. Picking up some tbolt clamps in the AM and I'll get back to everyone here.
chrisfullwood
Well-known member
definitely agree with below!!, take it easy on what you have, its easy to tighten this, and replace stuff until you destroy an engine, chill out on the boost, and be nice to it, until you figure out whats going on.
Quoting DR1665:
If you set base idle correctly (grounding out the ISC, all accessories off, engine/coolant at operating temp), and it still acts up, you might be looking at a failing ISC, a vacuum ("boost") leak, or some kind of tuning issue. Your mention of running 20psi suggests you have some mods installed, so it's possible something isn't tuned right.
If you've got cooling and idle issues, you really shouldn't be trying to force your way past them to 20psi. That's a recipe for disaster, imo. Double check your coolant level, make sure you "burp" the system to get the air out, and consider doing a compression test to get a bead on that headgasket.
Good luck.
Quoting DR1665:
If you set base idle correctly (grounding out the ISC, all accessories off, engine/coolant at operating temp), and it still acts up, you might be looking at a failing ISC, a vacuum ("boost") leak, or some kind of tuning issue. Your mention of running 20psi suggests you have some mods installed, so it's possible something isn't tuned right.
If you've got cooling and idle issues, you really shouldn't be trying to force your way past them to 20psi. That's a recipe for disaster, imo. Double check your coolant level, make sure you "burp" the system to get the air out, and consider doing a compression test to get a bead on that headgasket.
Good luck.
