I am installing gauges. Which temp port in these pictures is the one that I need? I'm guessing the lower one behind the water pump. '69 ninety eight.
Thanks,
Neil

 

No, it would be the one with two wires on it. The smaller diameter one behind the water pump is for the oil pressure switch.
However, I am not sure why your switch has two wires. Does it have the auto temp control?

 

I believe that those had COLD and HOT lights.

- Eric

 

Yes this car has lights for 'cold' and 'hot'. The sending unit next to the water pump must be water temp as the sensor for the oil pressure is next to the oil pump/filter at the rear right block.
Neil

 

Heres the temp sender circled in red...

 

I'm sure what you mean, as thee is no sensor near the oil filter.

- Eric

 

The temperature switch is located next to the thermostat housing not the water pump.... The switch near the water pump is for oil pressure according to the 69 shop manual..... Don't know why your oil switch would be located near the oil filter unless it was added as a back up (possibly a more direct reading)..............

 

The water temp sensor is definitely the one with the two wires. I just installed aftermarket gauges in my Delta. I have an Edelbrock intake manifold and was able to use an extra hole in the manifold for the gauge sensor, so now I have the gauge and the stock cold/hot idiot lights. I don't know if that's an option with the stock manifold, but it would be nice to have both if possible.

 

Ok....I was 'guessing' that logically the oil pressure unit would have been near the o-pump. This will make it easier to run the wire for oil pressure along the water temp wire. The 2 wires for the w-temp must be separate for the cold and hot light's. The green wire the green 'Cold' light? Or am I being too logical again.
Thanks,
Neil

 

Dark Green is Hot
Light Green is Cold.

The logical thing would be to take five minutes to look in the Chassis Service Manual instead of guessing.

- Eric

 

No, I don't 'guess'. Poor choice word. I've been tinkering with cars since my first one in 1954. I have manuals for many of the cars I've owned. This is my first Olds. The last 27 years I've had big Buicks including my current red Centurion convertible. I'm beginning to believe that Buick and Olds builders, even that they are under the GM corporation, did not 'lunch' with each other much. My Buick 455 and Olds 455 could not be any different. My Buick has 80k more miles on it than the Olds but both are awesome. Time to get a service manual....expensive so you guys are my best resource for now. At 75 I do not plan on undertaking any major mechanical redo's on my own. This one owner unrestored Ninety Eight is in great condition but has been stored in a shop for about 30 years. I about to install a 4 row radiator for towing our vintage Airstream. That's why I'm installing oil pressure. water and trans temperature gauges.

Thanks.
Neil

 

Getting biblical now?

Mayest thou find that sensor beforest thou passes from this earth.

 

We all make 'em sometimes.



Au contraire, mon ami.

1. Half the time we're wrong, or argue with each other so much, you don't know whom to believe.

2. We usually don't draw good pictures.

3. Expensive? Not at all - just go to WildAboutCars, and your manual will be right here, downloadable for free.
There is no doubt that a printed manual is better, but the digital version is adequate to answer the vast majority of questions.


Awesome!


Awesomer!!!


- Eric

 

Oy vey.

No, just using the second person familiar .

- Eric

 

If a used original Chassis Service Manual for $20 on ebay is too expensive, sorry but you're in the wrong hobby. This is the cheapest "tool" you can buy for your car.

And prior to the move to "corporate" motors in the late 1970s, each GM division had their own proprietary engine designs. These had nothing in common, despite similar displacements.

 

I'm fond of saying that the only part they share in common is the rotor inside the distributor.

Welcome to Oldsmobile, Neil. Nothing like a big 98!

 

Signed up at 'Wild About Cars'. Accessed the service manuals. Thanks....I'm retired from just about everything except cruising and towing our Airstream. If I need serious mechanical work I will take my cars to a professional AFTER learning as much as I can about a problem so that I won't be screwed. I just HATE paying for an hour job to reconnect a vacuum hose. I got manuals for most everything that I have/had except this Ninety Eight. No book shelf space left.
Thanks for the info....so far classic olds forum has been more helpful to me than my Buick chums.

Neil

 

Well, there's the distributor cap also.

 

I have both on my Buick 455. I mounted both the sensors to a 'T'. I have the stock idiot light AND gauge. However, I discovered that when the warning light comes on it's almost too late. Back in the '60s I had a Grand Prix where I had installed an aftermarket oil pressure gauge. The oil pump failed but according to my gauge I had less than 10 pounds pressure in all rpms but the warning light never came on. Without the gauge that Pontiac V8 would have been toast. I have always added gauges to the cars I've had that had that had no factory gauges. Now with towing heavy trailers I have added tranny temp gauges.
Neil

 

Oil PRESSURE senders will work correctly when mounted in a tee. Water TEMPERATURE sensors will not. The temp sensor must be mounted in a flowing stream of coolant. The tee is a dead end and will not produce correct readings on the sender, as you apparently found out. If your intake does not have sufficient ports to install multiple senders, you can get a fitting that splices into the upper radiator hose that has a bung for a sender. Not ideal, but better than a tee fitting.

 

You are correct. I checked my Buick. 7 years ago I installed gauges on it. I must have discovered that the temp gauge must be in the 'flow' and placed the sender instead in a port hole vacated from emission ports no longer required.


Neil