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Huge vacuum leak? + Oil pressure concerns


86RangerXL

Well-Known Member
Joined
Feb 28, 2022
Messages
45
City
Tallmadge, OH
Vehicle Year
1986
Transmission
Automatic
I've had my 1986 Ranger with the 2.9 for about a year now and finally got around to testing if there's a vacuum leak because of the real rough idle. I made a little smoke machine thing, blew the smoke into the system, and I see some smoke coming out from the left side of the thermostat housing, near the intake manifold. I also saw smoke billowing out of the carbon canister when I did this too. Does it look like smoke is coming through the intake manifold gaskets in the video I put below? Is the large carbon canister leak normal?

My other question was my oil pressure. My oil pressure has been on the high side for a while but it seems like its even higher now. It usually sits in the middle of the letter N in "norm" on the gauge. Recently, I've seen it go above the N and get scarily close to passing out of the "norm" section. I don't know what could be causing that, I'm not using too thick of oil, just the recommended 10w-30 with a little 10w-40 to top it off.

 
I have zero idea why smoke would be coming out of that area. Unless you maybe got a bad intake gasket...but that would be a stretch.

As far as the oil pressure, even though 86 has the better of the electric gauges (it actually reads pressure instead of like 87 1/2 and up thats basically on or off) its still electrical and not immune from wiring issues.

If its reading high chances are its the wire thats gotten messed up and is shorting out, or the sender itself is bad.

If all the gauges read high then its more then likely the voltage regulator behind the dash.
 
That looks like an intake leak to me. If you spray a little brake clean or carb clean on it does the idle change? I'll bet it does. An 86 used the old bi metal gauges so the reading could be affected by a sending unit problem, loose connection at the sender, poor engine ground or the constant voltage regulator(instrument voltage regulator) in the dash, or even a gauge problem. If it's the CVR, the gas and temp gauges will also read high by a corresponding amount. The later ones with magnetic gauges are actually idiot lights with needles- if the sender sees pressure the gauge gets a signal that sends the needle to about 2/3 of the scale.
 
I have zero idea why smoke would be coming out of that area. Unless you maybe got a bad intake gasket...but that would be a stretch.

As far as the oil pressure, even though 86 has the better of the electric gauges (it actually reads pressure instead of like 87 1/2 and up thats basically on or off) its still electrical and not immune from wiring issues.

If its reading high chances are its the wire thats gotten messed up and is shorting out, or the sender itself is bad.

If all the gauges read high then its more then likely the voltage regulator behind the dash.
Sender is brand new, voltage regulator is brand new. The temp gauge reads barely in the norm range which was a bit weird too cause I have a 192F thermostat like the original. I don't remember if I cheaped out on the oil pressure sending unit, but knowing me I probably did so it may just be a crappy unit. Could be the gauge though. Do you know if the carbon canister is supposed to be 100% sealed though? Smoke came out of that like it had no top on it
 
That looks like an intake leak to me. If you spray a little brake clean or carb clean on it does the idle change? I'll bet it does. An 86 used the old bi metal gauges so the reading could be affected by a sending unit problem, loose connection at the sender, poor engine ground or the constant voltage regulator(instrument voltage regulator) in the dash, or even a gauge problem. If it's the CVR, the gas and temp gauges will also read high by a corresponding amount. The later ones with magnetic gauges are actually idiot lights with needles- if the sender sees pressure the gauge gets a signal that sends the needle to about 2/3 of the scale.
Yeah I was thinking I could try that, I'll give it a shot later and see if it makes the rpms go up and get back to you. The other gauges seem to read fine, the temp gauge even seems to read a bit low. See my response to rusty ranger for a little more info
 
That looks like an intake leak to me. If you spray a little brake clean or carb clean on it does the idle change? I'll bet it does. An 86 used the old bi metal gauges so the reading could be affected by a sending unit problem, loose connection at the sender, poor engine ground or the constant voltage regulator(instrument voltage regulator) in the dash, or even a gauge problem. If it's the CVR, the gas and temp gauges will also read high by a corresponding amount. The later ones with magnetic gauges are actually idiot lights with needles- if the sender sees pressure the gauge gets a signal that sends the needle to about 2/3 of the scale.
Spraying starter fluid around the gasket seems to do nothing, but I don't think there's anything else over there that could be a vacuum leak so I have no idea where the smoke is coming from
 
If you don't see a stray vacuum hose under there, the only thing left is the intake gasket and that isn't a terrible job.
 

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