454 chevy temp sensor

One on each side of engine. Degrease the engine or get dirty. Go to auto parts store and look at it, then find them threaded into the side of the engine block.

It depends on the year of the vehicle and the model on where they put the temperature sender/sensor(s) for a specific engine. If you have a friend who knows someone at a repair shop (or if you do) call them up and have the people at the shop look it up in AllData (most shops these days use AllData it seems), sometimes we run into a problem at our machine shop and we have a couple different repair shops we call and have them look at the wiring schematic in AllData to tell us where a sender/sensor is on a head and/or block. Lot nicer knowing where it is, before opening the hood.

Your local library may have Motor manuals in their reference section and some of them show where the different things are located.

I tried to Google it to find the info, and not very good links were returned, so AllData info is probably your best bet. Most of the time, the sender/sensor(s) are in one or the other head, sometimes both, sometimes in the intake manifold. All depends on the year/vehicle the engine is in.

Ken

As MrChevy said. Depends. In the first series of big block chevys, the temperature sender was in the intake manifold water passage, next to the thermostat. In 1969 (I think) they moved the temperature sensors to the cylinder heads. Roughly 1/4 of the way back from the front of the driver's side head. Or 1/4 of the way from the back of the passenger side head, on the outboard side. It should be about the same height as the exhaust ports. If only one sensor is used, it should be on the passenger head, if a second is used both spots may be used. There could still be sensors in the intake manifold. If your vehicle was produced in the sixties, seventies, or early eighties, the wire got the temperature gauge was dark green. Like he said... depends. Hope this helps. If not send more specifics and I will try again.Good luck.

I was reading the post and I have a question,I bought a 1995 motor home and it has a 454 in it but I found out that a bunch of wires have been cut and I cannot find the sensors I want I think I have two one on each side that have one wire to it and I have one under the goose neck where the water comes in to the motor,now saying all this the motor home has a secound fan and i am told one of these work the fan telling it what teh temp is.And the temp guage does not work.I am trying to get it to work and the secound fan,can you help on this a little,I just hate to pay a mec to work that long running down wiring but I might be better off

Marvin

As you should know, you will need to do some work, and send additional information. All of the factory installed wiring should be enclosed by black electrical tape. That tape is thin, not very sticky, and very tight and uniform in appearance. The wire that used for the temperature gauge was dark Green in color. That should get your gauge reading again. If you find a blue wire that is in a harness, it would be for the oil pressure sending unit.

A sensor used for the electric fans, is best when it is sensing the water coming out of the radiator after it has cooled off. It can work if it is sensing the water in the engine, but not as efficiently. Check out what I have sent, and see if that helps sort things out. Good luck.

It would be a nice touch if you registered here. We would be able to better distinguish who has the problem, and who is just adding comments.

Hey Bob, I have a 93' RV with a 454 7.4L. I've been trying to troubleshoot a problem with gas mileage going down since I last had it's smog test done. I was getting around 15-16mpg with 50mph avg. Now I'm getting about 9mpg. I'm also seeing the check engine light coming on for about 10-15 seconds after being on the freeway for a while or climbing a hill. The codes it's throwing are 42 and 44. Today I pulled off the engine cover and discovered a broken plug hanging down onto the exhaust manifold. I eventually figured out it was originally supposed to go to the temp sensor on the passenger side. It's got a single green wire going to it, same as the gauge sender on the drivers side of the engine. I went down to the auto parts store, but all they have is what is in their computer and has 1/2 inch threads instead of the one that is currently installed which measures to be 27/32 or around 21mm (measuring outside of the threads). I have found sender converters online for 5/8 and 3/4, but nothing anywhere near 27/32" Any chance you can direct me to where I can get a new temp sender for this guy? Thanks -Al

I hate to tell you this, but That term 1/2" is a little misleading. !/2" pipe thread is actually tapered from 27/32" up to about 13/16". The temp sender that is shown in the parts catalog should fit. There are at least two sending units that could be listed. One id for the temperature gauge. This sending unit has always been slightly different than any other sender I can think of. It has a flat top on the connector that looks like a brass nail head sticking out of it. The wire connector slides on to the sender at a right angle to the centerline of the sender.

The senders that trigger a light, or a signal to the computer are all equipped with a 1/4" male spade connector, and the wire connector slides on in line with the centerline of the sender. This should help get you the correct sender.

Get the sender from the store, and compare it to the one you have. You will probably need a new wire end, But why do you need a new sender? good luck.

Hi Bob, thanks for your reply. I actually did purchase the sender at first, and it wasn't until I tried to install it that I realized the drastically different sizes. The new sender went straight through the hole without ever even touching the threads. The reason I need to replace it is that the connector was broken clean off. There is some contact still exposed on the old sender so I'm going to see if I can solder a wire to it today I just don't know if it's really going to hold or not. here's a couple pics of the broken connector

I'm hoping that this is the culprit that is affecting my gas mileage and from time to time throwing code 42 and 44, which has been happening since I had it's smog test done last year which is when I suspect it got broken off.

So, I talked to one of the guys at work today and you are correct, it turns out that what I have is a 1/2" Pipethread, and what Kragen/Oreily is trying to give me is a 3/8" pipe thread, and I have found 3/8" to 1/2" adapters online. My coworker also said that there may be a 3/8" hole on the engine also, in which case I would just need to get a plug, or use the broken sensor as a plug, finding that 3/8" hole may be a different story since this is in the RV, and I already can't see the whole where the current temp sender goes, I can only feel it, and use the camera to find it. At least I'm seeing possible successful outcome at this point.

from what I can see in the NAPA book the temp sender is 3/8" on your engine, and the coolant fan switch is 1/2"

the # for the temp sender is TS4052, and the fan switch is FS104.

The connector is different for each of these switches. If you have a NAPA store near you, ask them to show you a picture of the connector used on the switches. (it is in his buyers guide)

If no NAPA, go to your friendliest auto parts store, and ask him to convert these numbers to his brand, Then ask to see the connector ends. Good luck.

hrmmm... The plot thickens a little bit then. If it's a fan switch, what fan would it be turning on and off since the fan is not electric and is on a pulley. Also, according to my dash gauge I'm not having any overheating issues. The RV warms up to about 190-200 and just stays there. Even climbing the grapevine in california with the AC on, the temps don't read much about 200. That being said, the FS104 is much more of an exact picture of what I have. Also the connector on the TS4052 while being the same size on the outside, is shaped a little bit different on the inside. I was going to cut the original connector off and solder on a pin to connect to the new sender, but I'm beginning to think I'm glad I didn't.

1. 7.4L V8 OHV 16V FI 454 chevy Engine in a 1994 air-stream land yacht and I'm trying to figure out if there is only one temperature sensor or up as many a 3 of these. I have seen one one the intake near the thermostat and there are two others on each side but not sure if these are part of the temperature system. The problem is as I start the engine the gauge starts to climb for a while and than drops off a bit and than starts to go up again but than it will completely drop off and than jump back or it might not. Figure I would replace the unit but now not sure how many there are.

The wire for the temperature sensor should be a dark green wire. When disconnected from the sensor, the temp gauge should drop below cold, or above hot with the ignition on.

I HAVE A 1993 454SS. IM HAVING A HARD TIME ACQUIRING THE PASSENGER TEMP SENSOR. NO AUTO PART STORE HAS IN THEIR SYSTEM. THE CONNECTION ON MY SENSOR IS MELTED ALONG WITH PIGTAIL CONNECTOR. ANY ONE HAS A PART NUMBER?

MY CK1500 MISSES A LOT ON 2200 TO 2500 RPM ONLY. ITS VERY WEIRD. IVE CHANGED OUT......... FUEL TANK, KNOCK SENSOR. EGR SENSOR, EGR SOLENOID, FUEL PUMP, FUEL FILTER, DISTRIBUTOR(TWICE), SPARK PLUGS, INJECTORS, CABLES, AND TBI REPAIR KIT AS WELL.

Based on the info you've very helpfully provided so far, I found this guy at a nearby shop. link It has the exact same plug which is a good sign, although, I'm still very curious about the fan switch thing with there being no electric fan. Also I'm less confident about this causing my gas mileage problem as well.

Interestingly enough, although I'm betting you already knew this. There is an electric fan on the other side of the radiator. It's a much smaller fan than the one in back between the engine and radiator. Also I think its a second radiator of sorts, because it looks like only the AC lines are going through it. At any rate new TFS16 is now installed, and after the engine was running about 30 minutes the front electric fan finally came on. I would like to thank you again Bob for your assistance and pointing out that it could possibly be the fan switch and not a temp sender. -Al

Never mind buttering me up with thank yous. SEND MONEY. Have you cleared the trouble codes that were set? I have not looked up what they indicate, have you? Just see if the codes come back now. If the mileage does not return, that is next. Good luck.

Just got a 94 GBM motorhome with 454,temp gauge stoped working,grounded senser wire and gauge went all way over to hot and a buzzer went of,so I changed the senser and now it runs @ 200-220 degree...used to run 190-200 before.....wuts up with that??

Welcome to the insanity.

Do you have access to an infrared thermometer? If so, compare the two readings as the engine transitions from cold to normal temperature. If not, it is possible that the grounded sensor wire caused the dash gauge to be damaged. If you can not use the IR thermometer to compare, let me know. I have a chart that will tell us exactly how many ohms will make the dash gauge read on each degree number. Good luck.

na don't got access to infrared thermo gun, gauge works now that I changed sender,it just reads hotter than it use to.....

I will dig out the chart, you can check it with an ohm meter. Do you have access to one?

got a multi meter, ohm is the horseshoe shaped thingy rite? lol I just use it for the volt meter! lol

No! No! The horseshoe thing measures metric horsepower.

LMAO...Don't know much about using a multi meter other than the volt part....:O)

Ready, set, Go.

According to my chart your dash gauge should show 100 deg., 250 deg., and 320 deg.

There are also some other mid and high temperature numbers that might be on your gauge. So, here goes:It takes

1365 ohms to make your gauge read 100 degrees.

200 ohms = 180 deg

96 ohms = 220 deg

62.5 ohms = 250 deg.

28 ohms = 320 deg.

You can check both ways. Start with a cold eng, and watch the gauge. as soon as it reads 100, check the resistance from the connector on the sender to ground. same with the mid #. Or, you can go to Rasdio Shack, and get a variable resister( reostat) that can vary between 1365, and 0. adjust it to read what the numbers I sent you are, and then use it as your sending unit by grounding one of the connections on the reostat. Good luck, let me know if you need more help.

MY TRUCK STARTS GREAT FIRST THING IN THE MORNING,BUT AFTER I RUN TO TOWN AND LET IT SIT FOR 30 MIN. ITS HARD TO START. I FIGURED IT MAY BE THE COOLANT TEMP. SENSOR, BUT NOT FOR SURE. DOES ANY ONE KNOW WHERE IT IS LOCATED ON A 2000 454? OR IF I AM LOOKING AT THE WRONG PLACE I AM ALL HEARS. THANKS!!!!!!!

I would suspect heat soak. If the engine is at 180* when you shut off the engine, the heat in the combustion chambers has no place to go. As soon as the water pump stops turning, the heat starts to spread out throughout the engine. If you come back to your truck, the radiator has cooled some, but the coolant in the engine has been exposed to the combustion chamber heat, and not been able to pass the heat to the atmosphere through the radiator. A heat activated auxiliary cooling fan that is not switched off with the ignition switch will help some, but you probably going to have to beef up the starter system. Here is a test to check my theory. Put an extra charged battery in the truck, along with a good set of jumper cables. drive the truck until it is fully warmed up. Shut off the truck, wait 30 minutes, or whatever time is correct to make the "no start" problem to show up,and try to start. if it is turning over very slowly, use the jumpers. If that allows normal cranking speed, the starter system needs checking.

Start with load testing the battery. If replacement is required, buy as much battery power as you can afford. Next check the battery cables. The cables need to be clean, tight and corrosion free. Check from the battery to the starter, and from the battery to ground on the other post. If the cables are the least bit questionable, replace with #2 gauge cables or thicker. You can't have too thick a set of battery cables.

If all is good so far, you could have a week starter. That should show up is the battery load test gauge is connected to the battery and you try to start. Once again the quality of the starter is not something to skimp on. This engine combination is common in motor homes. The heat soak problem is so bad in some of them that there is a common repair done to them that includes a remote mounted starter solenoid, and a heat shield. That along with the electric fan should not be needed, if you have a strong battery, thick cables, and a good starter.

One note on starters. There are a new, smaller design permanent magnet starters available along with the older, larger design with electric magnets. I am no expert on the newer design, but I have some tips for you if you need to buy an older design model. Any Chevy starter that fits will work when all things are working fine, but if the starter was designed for a smaller motor application, you will have a hard time starting when hot. The GM starters used in passenger cars, and most light duty trucks, come in two lengths. The longer starters belong on your big block. They can be identified by the spacer between the leads coming out of the starter motor itself, and the starter solenoid that is mounted on the starter. If you have about 5/8" between the end of the solenoid, and the starter motor leads, you have the first of the good features. The other desirable feature is the four field starter. Inside the starter, there can be two, three, or four field coils. The best of the starters have two thin copper straps coming out of the starter motor that attach to the solenoid.

Trying to tell this to the rocket scientist behind the counter at Pep Boys, or Advance Auto Parts will get you nowhere. Here are a few vehicles that always had the correct electrical parts to make a really strong starter.

• All Oldsmobile Tornadoes, prior to 1973.
• Big block Chevys cars with manual transmissions. As a bonus, these had a cast iron mounting housings. Again back to the late sixties, early seventies.
• 455 four barrel Buicks, and Pontiacs. Probably the Cadillacs also, but check. Again the same years.
• Big block Chevy or GMC 1 ton trucks with automatic transmissions. Same years.

You might need to look at a few starters till you find the correct one you want. If need be you can swap the nose from your starter onto an Olds, Buick, Pontiac or Caddy starter. It is an easy job, and worth the effort. If this is beyond your skills, try to contact a reputable electric shop, and have them assemble one. Good luck, and let us know how it works out.

i know this is a old post but had to tell my story, 91 suburban 2500 454 starter would freeze up when hot . under the hood so hot that you couldn't lean against the fenders without burning yourself, i had to run water over the starter to cool it off enough to allow it to turn over. problem solved with a hi torque starter, plenty of air space around that skinny starter, never had another starter problem regardless of the 118 degree temps in So. Cal.

An automotive parts distributor?

On-line suppliers?

eBay (usual disclaimer)?

Alibaba (usual disclaimer)?

YouTube?

Direct from <...chevy...>?

Local scrapyards (w3w///broken.parts.daily)?

Is this a test?