Oh great, another gauge failure.


Indy GT

Yea, I got one...too
Mark IV Lifetime
Jan 14, 2006
2,526
Greenwood, IN
Kendall, you are correct again.

I knew the Boss water temp is also a calculated value from some transducer either in the head or head gasket. Yep, there is no traditional temp sending unit. And I am sure you had to figure this out with all your heat load calculations or measurements needed to develop the oil cooler option you offer for the Boss.

I thought about bringing that subject into the conversation post, but thought I would just focus on our FGT supercharger boost pressure topic.
 

PL510*Jeff

Well-known member
Mark IV Lifetime
Le Mans 2010 Supporter
Nov 3, 2005
4,876
Renton, Washington
Kendall, you are correct again.

I knew the Boss water temp is also a calculated value from some transducer either in the head or head gasket. Yep, there is no traditional temp sending unit. And I am sure you had to figure this out with all your heat load calculations or measurements needed to develop the oil cooler option you offer for the Boss.

I thought about bringing that subject into the conversation post, but thought I would just focus on our FGT supercharger boost pressure topic.

I'd bet a couple hundred lines of computer code is considerably lighter and much less expensive than a traditional installed temp sender. Not necessarily better but lighter and cheaper.
 

the Wizard

GT Owner
Jul 16, 2012
414
Los Angeles
But they have a temp sender, or at least a thermocouple, anyway.....but I guess a thermocouple is pretty cheap? Kendall, was it just a thermocouple under a head bolt?
 

cobra498

GT Owner
Jul 14, 2010
310
Central Ca;ifornia
Cylinder head temperature is a more reliable way of predicting overheating, a traditional water temperature gauge does not always indicate correct temperatures especially when there is no water in contact with the gauge sensor. I once lost an engine because I thought temperatures were fine when in fact I had lost a small brass block plug and most of the water before the engine began to slowly seize. I believe GM has been using CHT for quite awhile.
 

FBA

GT Owner
Dec 5, 2010
1,663
31.022340° N / 44.846191° W
That would be a simple zener diode. Figure out how to splice it into the connector from the gauge control unit to the gauge. If the socket/plugs were available it would be a simple pass through on all but the power line with the zener in the harness... It could be a single part if the gauges all use the same plug, but they probably don't to prevent someone from plugging the ammeter in the fuel gauge.
That would prevent backfeed - but not voltage spikes. You need a small circuit to filter the voltage spikes (rectifier, diodes, caps etc), which I said I believed was the problem early on in this thread. I would say revise that however, and I would now say that each gauge is simply a failure waiting to happen. There are I believe a few issues, the voltage spikes getting through the gauge circuitry, and the actual motors themselves not being robust enough to handle the duty cycles over time. That said, IMO, the easiest and by far cheapest way to resolve the issues is still Speedut. The entire changeover is peanuts compared to the value of any GT. It's probably one of the least expensive repairs you can make to these cars.

No disrespect, but when I see things like "class action lawsuit" posted on boards on the internet, I dismiss it; too many internet lawyers out there! I would say to each and every one of them, "get involved in a major lawsuit and come back and tell us how you feel after that". I'm no lawyer, but I have sued and been sued several times over the years in my businesses, sometimes I'm successful, and sometimes not. I'm not a proponent of frivolous suits and it's a very last resort when and only when all else fails.

I know enough to know that this isn't an actionable cause, no matter what.
 

Wwabbit

GT Owner
Mar 21, 2012
1,259
Knoxville, TN
Cylinder head temperature is a more reliable way of predicting overheating, a traditional water temperature gauge does not always indicate correct temperatures especially when there is no water in contact with the gauge sensor. I once lost an engine because I thought temperatures were fine when in fact I had lost a small brass block plug and most of the water before the engine began to slowly seize. I believe GM has been using CHT for quite awhile.

Yep. A CHT probe for each cylinder would be nice, particularly for highly tuned cars.
 

RALPHIE

GT Owner
Mar 1, 2007
7,278
... If you have a speedo or tach failure now or in the future, you'll have to roll the dice with an old-stock replacement or go the Speedhut route.

I was looking back at some of the assembly pictures that some of you took at Rally I (I wasn't there), and noticed one of the tachometer -

View attachment 32991

It shows a different vendor than Autometer - giving a Pollak PN: 273232-1. Is Pollak a division of Autometer?

Or is this for the connector? It seems to be for the tach -

View attachment 32992

The only thing I can find for Pollak is

http://www.pollakaftermarket.com/

So, perhaps the tachometer is not available from Autometer because they didn't make it?

Comments?

(They're in Canton, Massachusetts - maybe Andy or Ron could check it out....)
 
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PL510*Jeff

Well-known member
Mark IV Lifetime
Le Mans 2010 Supporter
Nov 3, 2005
4,876
Renton, Washington
The speedo unit I have also is labeled Pollak. Assembled in Mexico. Pollak part number 32311. Ford P/N 4GV7V-10849-AD.

Are/is Pollak listed as a vendor in the GT History book? My copy is 1300 miles away.

in 12/2011 the was an offer to sell a complete set of FGT gauges. I copied this from that ad:

"New gauges, never installed in a cluster. Tested at Autometer prior to shipment to Pollak, build date 079/04, have not been tested since."
 
Last edited:

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
Interesting. Maybe you guys are on to the reason Autometer isn't making the tach and speedo.

Anyone have any contacts at Pollak? A very small change they would be willing to make new ones, or maybe supply the shell and faceplate that we could mount Speedhut internals in.
 

cammerboss

GT Owner
Aug 30, 2006
42
parker colo
John ,I got a temp gauge if you need one.
What happened with the GT3 RS?
i need temp gauge if you have one, thanks, bob 3038985115
 

twobjshelbys

GT Owner
Jul 26, 2010
6,053
Las Vegas, NV
First, the last traffic in this topic is almost 5 years old, so availability is questionable.

However, you would be well advised to obtain replacements for the small gauges directly from Autometer. A Ford gauge whether from Ford or anyone else, will fail with the same probability as any of the other gauges. The new Autometer gauges look the same as the original factory gauges but have innards of a different design. And as long as you have the instrument panel off, it might be worth considering replacing them all at the same time.
 

07XL0027

GT Owner
Mark IV Lifetime
May 20, 2012
1,546
Austin TX
First, the last traffic in this topic is almost 5 years old, so availability is questionable.

However, you would be well advised to obtain replacements for the small gauges directly from Autometer. A Ford gauge whether from Ford or anyone else, will fail with the same probability as any of the other gauges. The new Autometer gauges look the same as the original factory gauges but have innards of a different design. And as long as you have the instrument panel off, it might be worth considering replacing them all at the same time.
I replaced all my small gauges last August. The cost for brand new gauges direct from Autometer was $225 per unit.
 

twobjshelbys

GT Owner
Jul 26, 2010
6,053
Las Vegas, NV
Having done a swap on the boost gauge before the Autometer replacements were available, if I had a single small gauge failure I would also change all of them out. It's not difficult, nor is it easy - call it tedious - to remove the bezel. Getting up under the dash with a bad back is a chore. Lots of blue tape and patience. I don't look forward to having to do it again. I cringed the other day when one of them didn't start up, but a on-off cycle brought it back to life.
 
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CampoLady

GT Owner
May 25, 2018
69
Out GT just left for Detroit to have Rich Brooks replace all the gauges with Speed Hut's.
We changed out our battery, checked the ground wire and oil pressure was still a no go.
Also a complete Fluid change. I'd also like to add a set of Standard Wheels. If you have them let me know.