URO Cylinder Head Temp Sensor

[Dauner]

Hi,

Rebuilding my 1989 911 3.2 and need to replace the CHT sensor that I cut the wire on during engine disassembly.

When I was researching upgrading to the 2 wire units with ground, people were saying they were roughly $100, so I wasn’t concerned about cost. Now I see the Bosch are unavailable, and the Porsche ones are $250-300.

Has anyone successfully tried the URO? They are < $100.

Really frustrating, as my one wire was working fine. I wish I would have done a recent price check before cutting wire.

I have also heard of people using 964 CHT in 3.2 Carreras. Can anyone confirm they have successfully done this? 1/3 of the price. Alternatively, does anyone have the temp/resistance curve of the 964 sensor? The 3.2 Carrera map is in the forums.

Thanks,

Mark

[uwanna]

Originally Posted by Dauner

Hi,

Rebuilding my 1989 911 3.2 and need to replace the CHT sensor that I cut the wire on during engine disassembly.

When I was researching upgrading to the 2 wire units with ground, people were saying they were roughly $100, so I wasn’t concerned about cost. Now I see the Bosch are unavailable, and the Porsche ones are $250-300.

Has anyone successfully tried the URO? They are < $100.

Really frustrating, as my one wire was working fine. I wish I would have done a recent price check before cutting wire.

I have also heard of people using 964 CHT in 3.2 Carreras. Can anyone confirm they have successfully done this? 1/3 of the price. Alternatively, does anyone have the temp/resistance curve of the 964 sensor? The 3.2 Carrera map is in the forums.

Thanks,

Mark

This is from the 964 service manual, can't see why the 964 CHT wouldn't work in
a 3.2.

[spuggy]

Originally Posted by Dauner

I have also heard of people using 964 CHT in 3.2 Carreras. Can anyone confirm they have successfully done this? 1/3 of the price.

Someone on RL says you can't buy a 964 CHT from Porsche anymore; only the 993/996 sensor is stocked. If you want to use it on a 964, you also need the connector kit to convert.

One guy reported that he bought a 993 sensor as it looked identical in the photos/diagram - but it was a different thread to the 3.2

Why don't you repair the one-wire lead you have? Or use the one-wire 914 sensor for $20.

Originally Posted by Dauner

Alternatively, does anyone have the temp/resistance curve of the 964 sensor? The 3.2 Carrera map is in the forums.

It's a Bosch NTC (Negative Temperature Coefficient) sensor; same semi-conductor technology as the one on the 3.2. These are nominally 2.4K Ohm @ 20C +/- 5%. Check against the table uwanna posted.

[sugarwood]

When someone makes a part supporting our cars, maybe give it a try. That way, they still keep making parts for our cars. If its bad, can you return it?

[Dauner]

Thanks guys,

Looks like I have a couple of options and some homework to compare curves. My current plan is to resolder the one I have and use as a plan B if I can’t find a reasonably priced used one. Will check out the 914 one.

Mark

[Bert87]

I have a URO sensor on the way, will update with my results.

[MIAdragon]

Originally Posted by sugarwood

When someone makes a part supporting our cars, maybe give it a try. That way, they still keep making parts for our cars. If its bad, can you return it?

Because doing a nightmare job twice sucks?

[Marc Bixen]

See my thread “More URO junk”

[Dauner]

It looks like the temp/resistance curves are identical in the 964 and Carrera 3.2 manuals.

Can someone please confirm that the threads for the 964 CHT sensor are M10? I can’t find this anywhere, including the part descriptions.

Other challenge is the connector and wire length. If someone can confirm they are the same, will save me time.

If there is an adaptor cable, I can’t find that available either.

Between Rennlist and Pelican, there is not one all inclusive thread that discusses replacing a 3.2 CHT with a less expensive alternative than the $250 Porsche one.

The inexpensive 914 CHT may work, but I can’t find the map, and I still have to modify connector. No big deal, but if possible I’d like things to look not super cobbled...

Thanks,

Mark

[UROParts]

Hi Mark, our Cylinder Head Temp Sensor 930 606 915 00 is now available, and we've sold 192 so far with no returns or complaints.

• Threads: M10x1.0
• Length: 630.0mm
• Pelican offers it here: https://www.pelicanparts.com/More_Info/93060691500.htm?pn=930-606-915-00-M253&SVSVSI=0819&DID=13864

You might want to also subscribe to this thread: Verify my CHT sensor test results

[famoroso]

FWIW, I just picked up my '87 911 from Jae Lee / Mirage International yesterday. He rebuilt the engine to a 3.4, during which time he installed a new genuine Porsche CHT sensor. The car developed a hot start (technically a hot no-start) issue post rebuild. He swapped the previous CHT sensor back in. Problem solved. Brand new, in-bag, $267 Porsche CHT sensor was dead on arrival.

[HaroldMHedge]

UROParts

In More “URO” junk, page 3, you mention that there are three tiers of parts first tier, middle tier and top tier URO Premium. So what tier are the Carrera head temperature sensors? It's difficult to tell on price alone since the Bosch price was about the same as the URO price but about 1/3 Porsche price.

Originally Posted by UROParts

Hi guys, here's some additional info about our history. https://apaindustries.com/company/about

We're definitely an American company, with our headquarters and engineering lab located in Southern California. Our parts are manufactured in many countries, including Taiwan, China, Thailand, South Korea, India, Pakistan, Germany, and the USA.

It's an oversimplification, but we basically have three tiers of parts. The first tier consists of sourced economical parts that are the exact same parts you'd get from other aftermarket brands, but we try to offer a lower price. The middle tier are parts we've developed in-house, which are typically higher quality than our competition but are still very competitively priced. An example would be many of our idlers and pulleys, which are equipped with high-quality, name-brand NTN or NSK bearings whenever possible. The top tier are our URO Premium items, which we painstakingly develop to be higher quality in materials and/or design than OEM, but sell for roughly the same price as OEM.

Examples of URO Premium would include the BMW water pump pulley mentioned above, which is made of aluminum instead of the fragile OEM plastic, or a variety of plastic cooling system connectors which we upgrade to aluminum. Or repair kits that allow you to repair an assembly instead of replacing it, such as some automatic shifter assembly components for Mercedes, or a vacuum seal kit that allows you to repair your expensive Mercedes or Volvo brake booster (installation video shown here). Or our Intake Manifold Repair Kit for Mercedes M272 V6 or M273 V8 engines, etc.

[UROParts]

Hi Harold, this is an item we developed to match OEM, so it would be the middle one. It's not designed to be better than OEM, so it's not a URO Premium item (which can be identified by "PRM" at the end of our part number).

[HaroldMHedge]

Thanks UROParts.

[Dauner]

Just to close the loop, I did end up purchasing a URO CHT sensor. Engine is finished, installed, and I have 200 miles on it. URO product seems to be working fine...

Mark

[mikedsilva]

Originally Posted by UROParts

Hi Mark, our Cylinder Head Temp Sensor 930 606 915 00 is now available, and we've sold 192 so far with no returns or complaints.

• Threads: M10x1.0
• Length: 630.0mm
• Pelican offers it here: https://www.pelicanparts.com/More_Info/93060691500.htm?pn=930-606-915-00-M253&SVSVSI=0819&DID=13864

You might want to also subscribe to this thread: Verify my CHT sensor test results

Sadly, my uroparts sensor has a problem. I bought it to use on my efi conversion and now have a flaky temp reading... turns out the connection to the sensor itself is intermittent so I need to get a replacement.

[PopsRacer]

fwiw
I used a URO in my 3.2, works fine. It's just a thermistor stuffed into a threaded housing. Not rocket science and certainly not $200+. My old 1-wire sensor was reading low across the board which would tend to be lean in theory. You almost buy the thing off the shelf at Mouser: https://www.mouser.com/ProductDetail/Vishay/NTCASCWE3152J?qs=%2FWiulJ9oly71tItYBKC28g%3D%3D

[Rodsrsr]

I've ran the URO sensor for the past five years and still working fine.

[UROParts]

PM sent Mikedsilva, we haven't had any issues with these but let's get you taken care of.

[mikedsilva]

fyi - URO Parts reached out to me here, and sent me a replacement. The new one works perfect.
The old one definately had some sort of break in the wiring (intermittent connection).

I think it's pretty amazing that a parts company, backs up their products so openly and supports the community in this way.

Thank you