78 beta oil pressure / coolant temp

[ckeen74]

Hi all,

Just got back from a trip to England where I picked up some front strut inserts for my sedan. However, I have a more pressing issue - when I ran the Berlina tour before I left, the car was showing low oil pressure at idle (despite being full on oil), which would go up with increased engine speed, and the temp would rise to an indicated 200 when doing a long uphill climb (I think it was about 85 outside that day). Of course, the red warning lamp between the temp & oil gauges was coming on. Any hints on what this might be? Bad sending units, or actual problems? There's no goop on the radiator cap, and the coolant was replaced by the PO. So I'm thinking the head gasket is okay and coolant is full...

Manual is on its way, hopefully I'll have it this weekend.

Thanks!

[Jim Keller]

I'm not real sure on the 78's but all my 81's and 82 Betas oil gauges start off up on the gauge but once the engine is warm, the needle will sit just at or a hair above the low oil line near the red light on the newer gauges, and will go up with engine speed, that is perfectly normal.

Your temps shouldnt' be getting that high and I suspect you may have a cooling fan problem. It should kick on right around 190 deg "F" and pull the temp gauge down to about 180 or so before shutting back down, if it has a problem, (bad ground, fuse, temp sensor in bottom of radiator or bad fan motor), your temps will go up on long uphill drives and long periods of sitting, like at a stop light or drive thru burger joint as it isn't getting enough air flow accross the rad fins to remove the heat.

Still, I have only had the fan come on with long periods of idling sitting still, never on the road, even with long uphill grades, so you probably have other problems beyound cooling fan

[davidb]

Always a good idea to replace sensors. Easy for me to say. Start
w/the ones in the head, most readily accessible. Then you're on
to the oil unit near the filter. Then [maybe] the fan sensor in the
radiator. Warning lights are just that, or "idiot lights" years ago.
If the gauges are acting flakey a warning light is doing just that:
"I'm warning you something ain't right w/me !"

[Jim Fierst]

Do you have any history of cooling system maintainence from the PO? Check that the fan does come on. You can take the two leads to the fan motor and ground the black one and give the blue one 12 volts and it should run. If it does then warm up the car and see if it will operate through the temp switch as Jim suggested. More probably you are suffering from a partially plugged radiator. A quick test of blockage is to remove the radiator and run a garden hose in the top of the radiator . Wrap a rag around the hose to plug up any space and then turn the water full on.. It should shoot a big stream out the bottom opening. You can do this test in the car by removing the top and bottom hoses but it will be messy and get water everywhere. Before you do the flow test I would find a good radiator shop that will replace your radiator core, if necessary.They can validate your findings on blockage. New radiators are probably NLA and I would not trust a used one. Also most shops won't do the "rodding" of your existing core anymore like in the old days. They say too many problems and insist on recoring.
Sort the cooling stuff out first and most of the oil issues will probably diminish . Also remember these cars called for 15W45 wt. oil and you can get a bit more pressure with 20W50.
As always keep us posted.

[SubGothius]

Another possible problem/solution: if the fan switch and fan power leads get cross-connected -- too easy to do, as both connectors on the loom side are the same type and color and located fairly close together -- I have read the fan would still run on cue but rotate backward! This may lead to a very odd combination of normal-at-rest but overheating-at-speed symptoms, as when the reversed fan kicks in when needed most at speed, it counteracts the airflow coming thru the grille and winds up having exactly the opposite of its normal, intended effect.

Can you determine whether the warning lamp is for coolant temp or oil pressure? If it it's for temp, and as long as the low-pressure lamp isn't winking on at all, then your oil gauge readings sound about normal IME. Plus, a properly-wired low oil pressure lamp/sender would also kill power to an electric fuel pump (if fitted), quickly starving the engine for fuel when pressure drops dangerously low.