Want another gauge?

Bret Ludwig did pass the time by typing:

And you can cross off an O2 gauge unless your still using a carb. Unless you want to see lights scrolling back and forth as the computer constantly hunts for the perfect mix. :)

The Vac/Pressure (or just Vac) is a good thing. It will tell you if you have a plugged cat, bad valve, intake leak, and is a good overall indication of engine health and happyness.

Yea.. I have one. It's neet but I'd trade it for a fuel pressure gauge.

A pyrometer might be more useful as an indication of overall rich/lean Tranny Temp for those that tow stuff.

A pyro, or correctly EGT, is very useful for tuning but if you are not rejetting or remapping your fuel delivery it's useless on a gasoline engine (or unless you have a mixture knob on the wheel like they did iin the 1920's-aircraft still do.) Diesel operators like them for driving technique.

The "vacuum" gauge, more accurately manifold pressure, is indeed useful. Especially on auto trans vehicles. It should be calibrated in absolute pressure, inches of mercury, which is not the customary automotive way. If you have a carb with a venturi vacuum port (for distributor advance) it's fun to get a double MP indicator, hook one to the manifold, one to the carb port-but not that useful. The days of cheap surplus aircraft instruments are over-they had radium dials and were bought back and buried.

Coolant pressure tells you nothing that coolant temperature doesn't. When your system is under pressure, there is a one-to-one relationship. After going through a couple of boil-overs with both gauges in place, you would realize this.

There is a vacuum indicator on my YJ. You are supposed to watch your shift points, so that it does not come on. Once you get the hang of driving the vehicle, it is useless.

One thing that I would like to see, is a gauge that tells you the "edginess" of the person in the passenger's seat, and when she is about to boil over. Then, you could back off on whatever you are doing. ;o)

Earle

If you have ever had a coolant loss you didn't smell or see you would know that in such a case the temp gauge may stay in the green until funny noises start happening. If the pressure and temp are NOT in sync you have a problem!

If the temp is high and pressure is normal you have a slow leak very probably.

If the temp is high and you have NO pressure you have had a catastrophic loss of coolant.

Gauges cannot take the place of periodic (i.e. every day) inspection of the ground under the vehicle, the under-hood area, etc. I don't need a gauge, to tell me that the coolant reservoir is empty. I am interested in this low-temperature, high-pressure, "funny noises" scenario. That would imply that the engine is getting hot, but away from the temperature sensor area, which is the cylinder head. That just doesn't make sense.

Earle

I lost a Slant 6 in an old surplus telco truck when the old radiator developed a pinhole leak on the highway. The hoses were harder than prom night and the engine started making loud noises and burnt steel smell all of a sudden. Temp gauge stayed over normal but not in the red the whole time. When the level got low enough the hole was covered by steam pressure dropped dramatically and fast-but by then the damage was done.

I wound up getting another slant 6 for fifty bucks and it is still running AFAIK....kid pulled it from his van, then found out how hard it is to convert Mopars from one engine to another.

The temp of the liquid was high as hell...but not the sensor. Go figure.

On my 98 TJ, I was 4-wheeling in some big icy mud puddles before I knew any better. The ice (I assume) broke off the collector off the bottom of my radiator and lost ALL the coolant in a big puddle. The problem was I had no idea, the coolant must have dumped while the radiator was submerged in the puddle because there was no steam or any other symptoms.

I got out of the woods alright, but as I was driving down the road, I noticed a loss of power. Then it started pinging, then it started stalling. The temperature gauge was actually a little on the LOW side, even though the engine was seizing. I should have stopped and got a tow after the pinging but I really didn't know any better at the time. At least I learn quick but the Jeep ended up needing a new short-block and re-machine on the sealing surfaces of the head.

A coolant pressure gauge would have been mighty handy at that time.

Admitting my own stupidity

-Jimmy

I see why you say this, but it is fixing the wrong problem. What you needed, was a dependable termperature gauge. In my experience, the temperature gauges that I have had worked for me. Defective gauge? Loose connection? Operator not looking at it? All of these can affect a pressure gauge, too.

Earle