Affordable gauge clusters

So after finding out the uncomfortable truth about what my oil pump looked like inside, I feel inclined to install an oil pressure gauge. A gauge flying solo will be hard to integrate aesthetically so I am considering buying an aftermarket gauge cluster. There are these triple gauge available anywhere, ranging about 50-100USD, see the attached picture for an example. I have worked some with sensors and electronics professionally and I am quiet sceptic measurement equipment in this price range can be decent. Especially when it comes to pressure. I see Honeywell automotive pressure sensors alone go for around 100 USD. On the other hand, probably don't need industrial precision here. Maybe 10%-20% inaccuracy is quiet alright in this context.

So this will be a vaque question, but do you have any general experience with these cheap gauge clusters and it that case what brand? Did you bother calibrating one? What about durability?

 

I run these Autometer Autogage pair.
They are both mechanical gauges, Good quality for the price.
https://www.amazon.com/Auto-Meter-2...efix=automater+auto+gauge+2392,aps,138&sr=8-1

 

I also run Autometer gauges, but I like the electrical senders. I did check my temp gauge with an IR Thermometer. Seems close.

 

I have VDO electric gauges in my 67 and I think it is time for an upgrade. The oil pressure gauge reacts so slowly it is almost useless.

 

Read many similar such stories.

They look pretty solid. But if the line to the oil gauge breaks it is very bad news I suppose? Or does it come with some sort of sender that does analog signal conversion in such a way oil cannot flow in this line? Sitting knee deep in hot engine oil realizing the engine is a piece of slag because of a new gauge wouldn't be a great deal of fun

 

I've never had the oil line break in my life....yet! Copper or nylon. Run the copper if you're worried....

https://www.ebay.com/itm/3047950485...EcNVg3TRSm&var=&widget_ver=artemis&media=COPY

 

I called up the Hansen Racing store in Sweden which have a good overall reputation. I talked to some guy who otherwise was doing some drag racing. They sell Autometer and he used them on this his drag car also, so some positive indicators regarding the quality of them. He had the same experience with the oil lines as you Mart, they actually seem to hold up.

What do you use for a thread sealer when connecting the sensor at the pump? I guess both PTFE tape as well as a liquid sealer like Loctite can add the risk of introducing something unwanted into the oil gallery. I suppose it is hard to get the surfaces clean enough for a liquid sealer, so PTFE tape would be the way to go? Some people say no sealer is needed on this NPT thread, but I am very sceptical to that. That sure doesn't work with a lower viscosity fluid like water at least, I know that for a fact.

 

I had nylon break once-soaked a belt with oil, pitched the belt, smoke from burning oil everywhere. Had to clean up the mess on the side of the road, teinstall the belt and melt the plastic line closed with a cigarette lighter. Not fun, 0/10 would not recommend. Run an electric sender.
Patrick

 

Ooh, sounds like a trip! Sure wouldn't want to end up there.

And then there is the maintenance aspect also. Having to mess with and care about another oil line going across the car when doing general maintenance. But it seems that electrical gauges clusters from reputable brands are a bit more expensive, didn't find one good option yet.

 

If you're using electric senders, they probably should be grounded thru the threads I would think.
Light amount of sealer so the ground is still there... maybe a Loctite thread sealant?

 

I use Teflon tape, judiciously. Make sure you wrap if correctly and don't over do it, also I only do the tip of the sender. so the body of the sender still makes a good contact. The only risk in my mind is when you remove it. Other wise the teflon should stay put and the oil pressure keeps it from making ingress.

The temp sender I put in dry.

 

My buddies used to lose their gage readings often while the hotbox oil fog and wire stink coated the windows from header pipes melting oil sender tubes or wires, the same fouled in clutch linkages, cracked tube flanges, deformed fitting ferruls, lines rubbed in a fire wall access hole, etc. etc. So I was always careful not to do these things and avoid the buddy payback abuse. So what happened? My gage body seam opened up driving one night with the lit gage dial needle still working and not noticed for awhile. To this day even with a huge mound of shop towels piled in front of the shifter to get home on, my carpet, wires and stereo have never rusted. Always keep vice grips stached to pinch lines closed, cut wires etc., duct tape will not save you when equadistant from nowhere my friend.

 

So I am more convinced then ever not to run a mechanical oil pressure gauge The electrical sensor reduces system robustness a bit also though, it is certainly another point of failure being added. But having an idea of the oil pressure appears more important.

In the end I cheaped out and bought an Auto Gage pressure meter at the local parts store, some AutoMeter ripoff I suppose. For that money saved, I could at least try it. I did calibrate it towards another cheap but new mechanical pressure gauge. At the and of the t joint there is a tire inflation valve. I used a tire inflator that also has a gauge and I applied increasing and decreasing pressure in steps a few times and compared. Both mechanical gauges read more or less the same pressure throughout the test. The cheap Auto Gauge read about 0.5 bar (~7 psi) lower for ascending pressures up to 5 bar. Then when descending it was a bit more consistent with the mechanical gauges, so it has some sort of hysteresis of around 0.5 bar. It is reasonable to assume the mechanical gauges showed something closer to true pressure, as it is unlikely they would have the same error. So the cheap-o-meter is pretty off, but it sure can tell me a lot more than the switch only so it will go in today.

Speaking of which, I checked the oil pressure switch that was mounted using this equipment. A pure joke. It went out at a very low pressure, maybe 0.2-0.3 bar or so. Then for going on again pressure basically had to be zero, and that after some delay. Will have to change that.