Water Temp (Coolant) gauge pegged intermittently high off scale

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Water Temp (Coolant) gauge pegged intermittently high off scale

April 11, 2018, 08:14:53 pm

The Water Temp (Coolant) gauge sometimes suddenly peggs intermittently high off scale, then returns to normal (185 degrees F). It usually occurs when engine is under heavy load, as if the sender wire is contacting ground when the engine is moving in it's mount. I checked the engine but can see no wires chafing.

On flat ground, the gauge reads fine for hours.

Anyone else had this problem?

Re: Water Temp (Coolant) gauge pegged intermittently high off scale

Reply #1 – April 11, 2018, 08:30:07 pm

Look for a grounded wire around the exhaust manifold, had that happen to our 270.

Re: Water Temp (Coolant) gauge pegged intermittently high off scale

Reply #2 – April 12, 2018, 03:42:39 pm

Yep. In my Safari this was driving me nuts. After trying a half dozen time consuming remedies, I found that it was the fuel gauge; it was old and no longer reliable. I bought the Silverleaf which communicated directly with the engine computer, giving me near instantaneous read outs that I can easily read and gives visual and audible warnings when my temps are elevated. This applies to my Foretravel as well. Occasionally, I will look down an my analog gauge and find it all over the place. Even if it were working consistently, I would not be able to differentiate between 205 and 215 degrees, given the scale.

Re: Water Temp (Coolant) gauge pegged intermittently high off scale

Reply #3 – April 12, 2018, 04:03:43 pm

If they doesn't work check for air bubble trapped in the system

Re: Water Temp (Coolant) gauge pegged intermittently high off scale

Reply #4 – April 12, 2018, 09:07:40 pm

Is this a possible cause because it happend in my U270? This is an excerp from the Ford forum:

1. "...sometimes the Oil Pressure gauge will move in synch with the temp gauge and go to the fully pegged position has only happened once or twice..."

2. Behind the instrument cluster, there is a "voltage regulator, a little silver box that regulates guage voltage....... could be a wire with worn shielding touching a ground.

Is there a gauge voltage regulator in Foretravels?

Re: Water Temp (Coolant) gauge pegged intermittently high off scale

Reply #5 – April 12, 2018, 11:09:01 pm

As Bill said...would suspect a "ground" issue.

Hans

Re: Water Temp (Coolant) gauge pegged intermittently high off scale

Reply #6 – April 13, 2018, 08:34:55 am

Check the wires at the back of the gauge. I have found that they or at least one seems to make bad contact sometimes and the needle does just what you're describing.

Re: Water Temp (Coolant) gauge pegged intermittently high off scale

Reply #7 – April 13, 2018, 05:37:47 pm

Where is the coolant temperature sender located?

I will also be diagnosing the problem from the dash gauge through the wiring harness.

The gauge itself would be suspect if tapping on it would change the needle behavior. It doesn't. Today, it pegged high for 10 minutes, then went back to normal. No amount of wiggling the connectors around and/or tapping on the gauge mattered.

Re: Water Temp (Coolant) gauge pegged intermittently high off scale

Reply #8 – April 13, 2018, 05:53:05 pm

The sender is behind the alternator and below the exhaust manifold.

Re: Water Temp (Coolant) gauge pegged intermittently high off scale

Reply #9 – April 13, 2018, 07:02:44 pm

All the sender does is vary the ground. It could be a bad sender. My 99 has VDO gauges if yours does it should be easy to find one.

Re: Water Temp (Coolant) gauge pegged intermittently high off scale

Reply #10 – April 13, 2018, 10:36:54 pm

Half my dash gauges had loose connections. Crimped them tighter then reinstalled

Re: Water Temp (Coolant) gauge pegged intermittently high off scale

Reply #11 – April 14, 2018, 05:00:07 pm

All electrical connections are tight. I:

- Replaced the terminal connectors at the sender. Cleaned the sender terminals. Seems to have made it worse.
- Re-seated the connector at the gauge.
- Did a "pull test" on all the connections.
- Checked the gang connectors behind the gauge cluster

Maybe I should order a new gauge and sender.

Re: Water Temp (Coolant) gauge pegged intermittently high off scale

Reply #12 – April 14, 2018, 05:59:07 pm

Quote from: Tim – April 14, 2018, 05:00:07 pm

Maybe I should order a new gauge and sender.

If those gauges are OEM, you could be right. I had SW gauges in both my SOB coaches, but a trucker friend turned me on to these, and every gauge was finally retro'd to: ISSPRO.com - Quality Gauges, Tachometers, Speedometers and more!

Re: Water Temp (Coolant) gauge pegged intermittently high off scale

Reply #13 – April 16, 2018, 06:16:36 pm

Resolved, hopefully. The sender has a round terminal. See photos. Someone jury-riged a connection by twisting a stranded 14 gauge wire around this terminal and applied silicon seal. It was loose. Could someone confirm that this is a photo of the coolant temperature sender?

I riged up a universal spring-loaded terminal (alligator clip) as a temporary solution to see if the issue is fixed. When I get to an auto parts store, I will buy a Series 56 Female terminal, the correct terminal for this round button style sender.

Re: Water Temp (Coolant) gauge pegged intermittently high off scale

Reply #14 – April 16, 2018, 06:36:16 pm

Tim,

In a word (actually two): GOOD GRIEF.

Find good (copper color, not green) wire and install a proper Eye.

If needed, keep cutting back until you find good wire. Butt connector to new wire and new eye.

Re: Water Temp (Coolant) gauge pegged intermittently high off scale

Reply #15 – April 16, 2018, 06:49:10 pm

A contender for a Darwin award for sure.

Re: Water Temp (Coolant) gauge pegged intermittently high off scale

Reply #16 – April 16, 2018, 07:12:00 pm

Tim according to wiring diagram B 2198 you have the wrong sender, it should have 2 white wires L1 and E77, you need to skin back the harness to find the wires.

Re: Water Temp (Coolant) gauge pegged intermittently high off scale

Reply #17 – April 16, 2018, 08:01:49 pm

Tim, I new I had seen that sender from somewhere, it looks like the ones we took out of small block Chevy's when we replaced the factory gauges.

Re: Water Temp (Coolant) gauge pegged intermittently high off scale

Reply #18 – April 16, 2018, 10:25:25 pm

There is another sender below this sender. It has two wires that I put two new terminals on. I wonder what the lower sender does?

Re: Water Temp (Coolant) gauge pegged intermittently high off scale

Reply #19 – April 18, 2018, 08:54:37 am

Update: My prior post mentioned a bad connection for the coolant temperature gauge. This is true, but it is for an added aftermarket guage, which was also fluctuating rapidly. Go figure: Two bad senders!

I ordered a new coolant Temperature Sender Switch Equivalent to VDO 323-099 from Amazon. It will arrive in an Amazon Locker here in Albuquerque, NM on Thursday.

Questions:
1. When removing the sender, will coolant come gushing out?
2. When removing the sender, will air bubbles be introduced, robbing coolant of one or more cylinders?
3. Will the bubbles be flushed out once the coolant pump operates?
4. Should the bubbles be bled? If so, how?

Re: Water Temp (Coolant) gauge pegged intermittently high off scale

Reply #20 – April 18, 2018, 09:02:22 am

Do theguages share a ground in some fashion?

Re: Water Temp (Coolant) gauge pegged intermittently high off scale

Reply #21 – April 18, 2018, 09:57:35 am

Quote from: Tim – April 18, 2018, 08:54:37 am

Update: My prior post mentioned a bad connection for the coolant temperature gauge. This is true, but it is for an added aftermarket guage, which was also fluctuating rapidly. Go figure: Two bad senders!

I ordered a new coolant Temperature Sender Switch Equivalent to VDO 323-099 from Amazon. It will arrive in an Amazon Locker here in Albuquerque, NM on Thursday.

Questions:
1. When removing the sender, will coolant come gushing out?
2. When removing the sender, will air bubbles be introduced, robbing coolant of one or more cylinders?
3. Will the bubbles be flushed out once the coolant pump operates?
4. Should the bubbles be bled? If so, how?

If done quickly very little coolant loss and when running it will self bleed.

Re: Water Temp (Coolant) gauge pegged intermittently high off scale

Reply #22 – April 18, 2018, 01:02:18 pm

Yes, the analog resistive gauge and the warning switch share the same sender and ground. Per another post, I will use a thin wrapping teflon tape on the threads. This tape will be cut by the engine threads so the ground will make contact.

Re: Water Temp (Coolant) gauge pegged intermittently high off scale

Reply #23 – April 19, 2018, 10:58:00 am

Photo of the new dual sender. Hope it works.

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