67 Electra Running Hot?

[dmfconsult]

Looking for some advice before I start changing parts. I ran the Electra for a short drive a few days ago and while out, I tested the brakes with a hard stop on a quiet road. The car started to run rough (which sometimes happens) but it wouldn’t smooth out at idle.  Driving was fine just wouldn’t idle well. A few blocks later the Hot light came on.  The problem is, it wasn’t hot.  The top radiator hose was hot, as was that side of the radiator, while the outlet side of the rad was cooler. My infrared thermometer said about 185* at the T Stat housing.  After seeing that I limped the car home but it wouldn’t stay running unless I popped it into neutral when coming to a stop and increasing the rpms. 
 

I’ve gone through a few things today and everything seems in order.  Dwell/Timing is set correctly, the temp sensor seems to work as it reads cold and goes off when it should. After a cold start today the car settled down to a smooth idle at about 650 rpm and it didn’t replicate the rough idle. Hot light came on again after a bit and the highest reading I could get on the infrared thermometer is 203* (I think the stock 195 T Stat is in there) and upper rad hose is hot, indicating T Stat is open. 
 

A few items I’ve done recently:  I just replaced the Heater Core and hoses. Last July the transmission was rebuilt. There has been what feels like an intermittent “slip” that I thought was transmission related but I could never replicate it for the shop. Because it’s not consistent it might be related to something else (I’ve read coil or condensor failing could cause a slip symptom). 
 

The rad has been recored several years ago and the water pump is a few years old. I put a new fan clutch on a couple of years ago.  Coolant is standard 50/50 split. 
 

The car has never acted like this. Could the sensor be malfunctioning?  I’m also thinking the T Stat may only be partially opening so I may replace it with a 180* one. 
 

The Hot light is supposed to come on at 243* and I don’t get any readings close that. Any other ideas?  I would certainly appreciate it!

[EmTee]

It sounds electrical to me.  Check the voltage at the coil with the key ON engine OFF.  How do the points look?  Condenser??  Do you have another 'known good' coil?  The HOT light is supposed to come on when cranking to verify the bulb.  Could there be an ignition switch issue?  It seems like there may be low voltage to the ignition, which improves at higher RPM when  alternator output increases...

Edited May 24, 2020 by EmTee
typo (see edit history)

[JohnD1956]

10 hours ago, dmfconsult said:

The car started to run rough (which sometimes happens) but it wouldn’t smooth out at idle.  Driving was fine just wouldn’t idle well.

 

Sounds like a vacuum leak.  Is the hose going to the booster flexible and not cracked at the connection points?

10 hours ago, dmfconsult said:

the Hot light came on.  The problem is, it wasn’t hot.  

 

10 hours ago, dmfconsult said:

My infrared thermometer said about 185* at the T Stat housing.

 

10 hours ago, dmfconsult said:

I just replaced the Heater Core and hoses.

 

First thought is that the rough running and this issue are not related.  Just coincidental that they are happening at the same time.  May I ask if you are getting heat out of the heater?  If not may be an air bubble in there compromising water flow.   Also could be the temp light switch has a compromised wire insulation problem at or near the switch.  I understand those two light switches are hard to come by so I would be careful with the one you have.

 

10 hours ago, dmfconsult said:

 Last July the transmission was rebuilt. There has been what feels like an intermittent “slip” that I thought was transmission related but I could never replicate it for the shop. Because it’s not consistent it might be related to something else (I’ve read coil or condensor failing could cause a slip symptom). 

 

I would think any type of coil or condenser failure would feel like an engine stall, not a tranny slip.  However, this may also be a vacuum leak situation at the vacuum modulator valve on the trans.  

 

Good luck  Doug.  It's especially tough when several things are happening at the same moment.

[dmfconsult]

Thanks very much for the replies. Here’s some more info.

 

Points and condensor look fine to me although I haven’t replaced them in years (this car doesn’t see a lot of miles). I do have a brand new coil that I think I will drop in but I’ll check the voltage on the current one first. I don’t think the hot light has ever come on when cranking, but the cold light has and does. I’m hoping it’s not an ignition switch but the chassis service manual also indicates that as a potential issue.  I may also just replace the points and condensor anyway and keep the current ones as spares. 
 

the vacuum hose to the booster was replaced several years ago. It’s now quite hard but I don’t think it’s cracked as I looked it over pretty carefully yesterday but I’ll replace that given how hard it is.  
 

I am getting heat John, first thing I checked after replacing the core, but I guess it’s still possible there is a air pocket. I’ll run the system without the cap for a bit to try and bleed any air off. 
 

The vacuum modulator was changed out with the tranny rebuild but I’ll look at that when I can get the car running long enough to try and replicate that issue.  
 

The wires going into the sensor are a bit crusty And the insulation looks cracked right at the point the wires enter the connector. Not sure what I can do about that, but I’ll carefully depin the wires and see if I cover any exposed wire. A new two pole sensor is available from rock auto so I might pick one up. 
 

I’ll go through these step by step and see if there is any change. 

[JohnD1956]

2 hours ago, dmfconsult said:

The wires going into the sensor are a bit crusty And the insulation looks cracked right at the point the wires enter the connector. Not sure what I can do about that, but I’ll carefully depin the wires and see if I cover any exposed wire. A new two pole sensor is available from rock auto so I might pick one up. 

 

There is a liquid insulation which can be bought at the hardware store.  That can be painted on any cracked or bare wires to repair the insulation.  I have no idea how long it will last.  I have also used blue silicone gasket maker on some mouse nibbled wires on my little station wagon.  These were the fuel injection wires.  Been running like that since I bought it.  

[Smartin]

If the problem did not happen the next day, it is likely not a vacuum leak. 

 

I would look at replacing the t-stat with a 180, and replacing the temp sending unit while you're at it.  Those are both pretty easy swaps.  Don't go tearing the car apart without eliminating these simple things first.

[60FlatTop]

15 or so years ago the HOT light on my '64 Riviera started acting funny. Then it would come on within a minute or so of starting. I stuck a temporary gauge in place of the sending unit to test it. Seems to be the sending unit. I have been opening the hood and checking for a decade and a half, give or take.

Bernie

 

Edit: Those look like lock washers under the exhaust manifold bolt heads. I wouldn't recommend that today. I'll check after supper and get them out of there. Must be from when I changed the engine right before the turn of the century.

Edited May 24, 2020 by 60FlatTop (see edit history)

[KongaMan]

I had a similar problem on a vehicle once.  It was a bad ignition switch.

 

I was too lazy to disassemble the steering column to replace the switch, so I put a jumper across the switch (from 12V to IGN terminal) with a toggle switch on it.  Start the car, turn the toggle switch on.  Shut off the car, flip it to off.  Kind of a PITA, but it worked flawlessly.

[dmfconsult]

Thanks everyone.  Haven’t had much of an opportunity to do to much today as the honey do list was long. I have got both hot and cold lights on with ignition to ON. Have 4.9 volts at the coil with ignition ON but engine not running.  Vacuum hose to brake booster is still in good shape, no cracks. 
 

I think i will repair the wiring and replace sensor and t stat. I always felt the car ran too hot anyway so I think a 180 T stat would be a good change.  I’ll also inspect the wiring to the ignition switch just to confirm I didn’t pull something when changing out the heater core. 
 

Thanks for the advice, I’ll let you know how it goes once I get the parts. 

Edited May 25, 2020 by dmfconsult (see edit history)

[dmfconsult]

Is there any thread sealant required for the sensor?

[KongaMan]

1 hour ago, dmfconsult said:

Have 4.9 volts at the coil with ignition ON but engine not running.

 

Seems a little low.

[Smartin]

I usually see around 5.5 volts, but I don’t think that has anything to do with the current problem.

[KongaMan]

46 minutes ago, Smartin said:

I usually see around 5.5 volts, but I don’t think that has anything to do with the current problem.

Nor do I; I'm just sayin...

 

BTW, when I was diagnosing my ignition switch problem, everything looked good in the static tests.  It wasn't until I put an analog multimeter on the coil and drove around (windshield wiper makes a great clamp ) that I could see the needle crater in time with the engine stumbling. 

[dmfconsult]

Thanks guys. I should clarify, it was 4.9 volts pole to pole, but 5.3 volts positive side to a good ground.   I do have a new coil in the parts cache so will switch them out and see if I notice any difference (once I can actually go for a drive of any length). 
 

I also noticed my oil light is not working now either. I think that is a byproduct of the tranny work so I’ll trace that as I think it’s wiring related as well. I think I’ll switch over to gauges soon 🤔
 

After many years of trouble free service, the Electra is really testing me the last few years!!

Edited May 25, 2020 by dmfconsult (see edit history)

[EmTee]

5 Volts at the + coil terminal seems low to me...  I would expect 7 to 9 volts.  Check again, wiggle the key (i.e., slightly rotate the switch back & forth) and see whether voltage changes.

Edited May 25, 2020 by EmTee (see edit history)

[Smartin]

Fix it until it breaks, Doug!

[dmfconsult]

2 hours ago, Smartin said:

Fix it until it breaks, Doug!

Hey, that's the easy part!  Even I can do that...

[KongaMan]

IMHO, I don't think it's a cooling problem.  Rather, I agree with EmTee that it's likely electrical.  More specifically, I'd guess that the temperature light is related to the engine running rough (i.e. almost stalling).

 

In any event, the engine running rough is a bigger problem than an inadvertent idiot light.  I'd get that sorted first, then see if the temp light is still acting up.

 

Not sure of the circuitry in a 67, but you might also check the VR.  If the output dips that could explain both rough running and the light.

[dmfconsult]

I will check the regulator as well, but the HOT light replicated itself in the garage on the weekend and the idle didn't change at all, so not sure what caused the running rough symptom, but it hasn't recurred so far.  Could the lowish voltage at the coil be reflective of the VR?  If the new coil puts out a similar voltage reading, I'd be looking for other causes.  I'm going to proceed with the thermostat now, just because I think a 180 degree one is he way to go and repair the wiring on the temp sensor.  I've also looked into the oil pressure sender and the insulation on that wire is pretty crispy too, so looks like I have a bit more wiring repair to work through.  Any more problems and I'll have to move this topic to the Me and My Buick section!

 

I appreciate all the help guys, I really do!  I work long hours in the week and weekends are usually busy with work around the house and family obligations, which doesn't leave me a lot of time to play with the cars, so bear with me as I try and get through this ever lengthening list. 

 

Cheers,

Edited May 26, 2020 by dmfconsult (see edit history)

[dmfconsult]

Well, this now seems confirmed as an electrical problem.  I switched out the coil last night and the "new" coil reads 5.3 volts at the positive terminal, exactly the same as the old one.  The major difference is now both HOT and COLD lights remain on at cold start up.  The COLD light turns off once the engine warms up a bit, but the HOT light stays on, even though it's not close to HOT.  Once the car comes off choke, the idle is a bit rougher than usual (likely a drop of about 50-100 rpm), but it stays running. 

 

Given the COLD light works, I don't think the sensor is bad, so I'm left to checking the wiring to see if it's grounded somewhere or perhaps something is going on with the ignition switch.  Or as @KongaMan suggests, is something going on with the voltage regulator?  According to the manual, the car has to be at operating temperature and running to check the VR, so I haven't done that yet as I've been worried about overheating, but I do have a spare VR that was working when pulled (I changed to a Delco Remy one), so I could try that before digging any further. 

 

The ignition switch I'll check as I could have jostled something when removing the ducts and distributor box when changing out the heater core.  Electrical is not my thing, so I'm going to get over my head quickly!

 

Cheers,

Edited May 26, 2020 by dmfconsult (see edit history)

[dmfconsult]

Brief update:  After being encouraged by @JohnD1956, I depinned the connector to the temp sensor and sure enough, the wire on the HOT side was barely attached to the connector.  It had been bent there when entering the connector and the break was really out of sight as it is right at the crimped connection.  The fact that the light remains on would indicate a broken connection, and I have to assume that the wire was barely making contact before, and the rough idle finally finished the wire off.  I have ordered in some new connectors and will splice those in after they arrive.  I did a look at the ignition switch and all wires are properly connected there. 

 

This doesn't solve the rough idle once the car warms up, but I'll get the HOT light resolved (hopefully) first, then I'll feel a bit more comfortable running the car to operating temp to diagnose the other issue. 

 

Cheers,

[JohnD1956]

1 hour ago, dmfconsult said:

The fact that the light remains on would indicate a broken connection,

 

Just to be clear, disconnecting the wire at the sensor should break the circuit and the lights should not go on except for when starting the car.   According to the wiring diagram you shared with me, the temp light circuit is grounded in the ignition switch for when you turn the key to the start position.  Once started the ground in the ignition switch should be broken mechanically. This is apparently to provide the test of the  lightbulbs on both sides of the  temp circuit before the car is running.

 

When the car is cold the cold light would be grounded through the sensor additionally.  And unless overheating the hot light should be off.  And disconnecting the wire at the sensor should result in no cold or hot light when the car is running except for the afore mentioned test period. With the sensor disconnected you should not have either light on while the car is running and if you do, then there is a short to ground in one or both wires to that sensor.  

 

What may have been happening was the wire for the hot light may have been touching the wire for the cold light  at the break, and grounding the hot light as well as the cold light when you were first starting it.  But the hot light coming on after warm up and without the cold light or overheating still indicates there is a short to ground in the wire leading to the hot light.  

 

Since this all started with replacement of the heater core I think you should look around the heater core's plenum to make sure a wiring harness did not get pinched between the plenum and the firewall.  Since that harness includes the wires to the coil if it is pinched  that may be the cause of the rough idle too. 

[dmfconsult]

Thanks John. I’ll double check the wires again but I was fairly careful with the wires  when the box and plenum we’re going back in. This issue didn’t appear immediately after as the HOT light developed after some running. It’s possible something for stretched when the plenum and box were coming out. 
 

With the state of those wires, they needed to be repaired anyway so not wasting time. 

[dmfconsult]

So some “progress”...  I had my two sons, who are home from their Computer Engineering studies due to COVID, solder in some new connections for the temp sender and no change, hot light staying on but cold light operating normally. Not a loss though as those wires were barely hanging on anyway and the boys like helping me with the Old tech big car. 
 

decided to turn my attention to getting the factory speakers working with the radio. Some previous owner had wired in an after market stereo and speaker and changed all the wiring.  While I was tracing the speaker wires I nudged the wrapped bundle of wires for the instrument panel and the hot lights flickered and turned off. I now know where to focus my attention to look for a short as “no light” both running or with key to “on” means open circuit. 
 

What’s funny is I’ve owned the Electra for 18 years and I can’t recall if the HOT light was ever on with the ignition switch to the ON position. Oh well. I’ll focus on that wiring next then test drive the car to see if the rough idle resurfaces. 

Edited June 7, 2020 by dmfconsult (see edit history)

[dmfconsult]

Need some pro advice and I’m almost embarrassed to ask, but I will anyway...  I think I’ve traced my idle issue to a failing PCV valve. I’ve pulled the old one and it’s pretty plugged. 
 

The new one won’t slip in the grommet despite the application of a bit of oil to assist and I’m hesitant to hose it down with lubricant as I’ve never had to before.  Any tips on getting the new one past the old hard grommet?  I stopped myself from breaking out the hammer. Or do I pry out the old one and install a new softer one? 
 

Thanks in advance!  

Edited June 16, 2020 by dmfconsult (see edit history)

[KongaMan]

3 hours ago, dmfconsult said:

Need some pro advice and I’m almost embarrassed to ask, but I will anyway...  I think I’ve traced my idle issue to a failing PCV valve. I’ve pulled the old one and it’s pretty plugged. 
 

The new one won’t slip in the grommet despite the application of a bit of oil to assist and I’m hesitant to hose it down with lubricant as I’ve never had to before.  Any tips on getting the new one past the old hard grommet?  I stopped myself from breaking out the hammer. Or do I pry out the old one and install a new softer one?

There ya go.

[Smartin]

If you install a new grommet, be sure to lube the new PCV valve before installing in the new grommet....it will want to push through the intake hole and you'll be fishing it out with a coat hanger.

[EmTee]

I'll bet the old PCV valve could be revived with a good soaking in carb cleaner followed by a few shots of compressed air.

[dmfconsult]

I may try this for now.  2 issues have come up:  (1) I've discovered that all the replacement PCV valves I've looked at are slightly larger than the one I pulled out, which given the hardness of the old grommet, is making it impossible to insert; and (2) I've researched grommets and apparently there are a number of problems with the size of replacement grommets as the repo's have them slightly wrong.  It's looks like there are 2 good replacements, but one of those suppliers won't ship to Canada and the other wants $27 to ship. 

 

The old PCV has loosened up a bit just sitting on the bench so I will spray it out a bit and reinstall as I want to drive this car.  I'll order the new grommet and PCV from the same place once I get over the shipping price shock and replace it later.  

[EmTee]

It's probably just a piece of carbon/coke keeping the valve from closing.  You have nothing to loose by trying to clean it out. 

[dmfconsult]

Cleaned and reinstalled. I can focus on wiring again for a bit and order the new PCV and grommet to replace later. 

[dmfconsult]

Should update this thread on progress. I found the source of the hot light. The ground to the ignition switch was depinned and hanging loose, which now makes sense as I don’t recall the hot light ever being on with the ignition switch to ON. I must have pushed the loose wire into a position where it was grounding against something when I removed/adjusted the duct work out of the way to get at the heater core. 
 

The rough idle seems to have been solved. Not sure exactly what the issue was but points were a bit rough so changed them along with condenser, coil and cap. A couple of spark plugs were also fouled so replaced those as well.  Been going on short trips to work it out and it seems to run better each time as I go further. 
 

The car is also running right at the temp it should be given this hot weather so no issues there. 
 

There’s a few more things to do, but I needed to stop working on it and start driving it.  I kept hearing @Smartins words.. fix it till you break it!

 

I did mess up when putting the dash pad back on, I put a little too much pressure on it and cracked it 🤬. Luckily I got a lead on someone who could repair it, not cheap but better than trying to find a replacement. 
 

Before:

After:

 

Hopefully I get some luck for the rest of the driving season and this car goes back to being relatively trouble free!  Crossed this lucky number on a recent drive (I was pulled over when I took the pic)

Edited July 22, 2020 by dmfconsult (see edit history)

[dmfconsult]

I think I'm going to start a thread in Me and My Buick on this car, but wanted to finally bring closure to this issue of intermittent poor idle and stalling in case someone is having similar problems.  After a summer of testing and tuning, the car would still idle poorly at times when warm, but the temps were good holding between 195 and 200 typically.  With most other causes eliminated, I decided to install an electric fuel pump to help the mechanical pump out and hopefully eliminate the "vapor lock" type symptom of running rough then stalling out.   With that done, I still wasn't happy with the responsiveness of the car.  The fuel pressure was good, the timing and dwell were set correctly, vacuum was good, so I decided to look into the carb.  

 

It turns out that the rebuilt QJet on the car had a slightly incorrect gasket between the base plate and the air-horn as it was missing a small ear near the primaries and idle tubes. This resulted in an internal air leak, which I think contributed to the poor running condition, particularly under load, as the fuel mixture would lean out too much.  With that now repaired, the car is much more responsive and runs like it should.   The weather is not ideal right now to take it for a lengthy test run, but look forward to trying that the first good day I get!  Hopefully these stalling problems are behind me and I can enjoy the car on long drives like I used to!