Another catalytic converter question.

[Paul Higg]

Does anyone know what the temps should be on the cats? I was told they should be hotter on shut down than they were when the engine was running. Is that true? I'm going to shoot them with a digital temp gun this week and I need to know what it should read.

Also, if I shoot the temp gun at the engine when it is running what temp should it be? Will it match the ECT gauge on the speedo?

I appeciate your help.

Paul

 

[Paul Higg]

Update if anyone would like to take a stab at this.

I measured the stock cats I have when the engine was ran for 22 miles while it was running. Left 300 degrees, right 275 degrees.

After it was off for one hour they were reading 136 degrees.

Also, is this normal? My ECT (which is GM and new) was giving a speedo reading of 228 and the fans were on but when I shot it with the temp gun the ECT itself was reading 208 degrees.

Thanks

Paul

 

[JimBobC4]

I measured the stock cats I have when the engine was ran for 22 miles while it was running. Left 300 degrees, right 275 degrees.

After it was off for one hour they were reading 136 degrees.

Also, is this normal? My ECT (which is GM and new) was giving a speedo reading of 228 and the fans were on but when I shot it with the temp gun the ECT itself was reading 208 degrees.

Thanks

Paul

Paul,

Just for kicks I shot a converter with a temp gun at my buddies shop today on a Porsche and it was about 285 degrees. It was a brick type cat like on our vettes so I guess your close.

 

[Paul Higg]

Thanks, now how about this? I shot the right manifold when it was running and after a 22 mile drive and it read 550 degrees!

 

[gmjunkie]

Thanks, now how about this? I shot the right manifold when it was running and after a 22 mile drive and it read 550 degrees!

Why wouldn't it be??Thats the Hottest part of the exhaust coming out of the head!!As far as Temp of the converters,275-450 would be about par depending on the ambient temp!!Some vehicles even run a little Hotter!! Now if 1 was running 325-350 and the other running 550-600,I'd be doing some Checking to see whats up!! You don't have a Problem,Don't try to fix it!!!

 

[Paul Higg]

Thanks Junk, no, I wasn't looking for a problem, I was just curious.

Now, maybe you can answer my first question. I shot the ECT sensor and it read about 208 but the speedo coolant said 238, but the water pump was reading 238. I shot it at the base of the ECT sensor, the bronze part.

 

[gmjunkie]

Thanks Junk, no, I wasn't looking for a problem, I was just curious.

Now, maybe you can answer my first question. I shot the ECT sensor and it read about 208 but the speedo coolant said 238, but the water pump was reading 238. I shot it at the base of the ECT sensor, the bronze part.

Steel,Brass and Aluminum Absorb,Transfer and Dissipate Heat differently!!

 

[Paul Higg]

Good point Junk! Duh! I never even thought of that. :bash I shot bronze on the base of the ECT sensor, and steel on the water pump. Someone slap me!

Thanks again Junk.

Another question, when I had my head practically under the car when it was running yesterday shooting the cats, I could hear that clicking noise pretty loud. It is new. It sounds like it is coming from both sides and it is loud under there. But I can't really hear it from above. Could it be oil related? It sounded like it was right inside the drip pan but I know there's no moving parts in there. I wonder if it IS the lifters?

Thanks again Junk.

 

[gmjunkie]

Good point Junk! Duh! I never even thought of that. :bash I shot bronze on the base of the ECT sensor, and steel on the water pump. Someone slap me!

Thanks again Junk.

Another question, when I had my head practically under the car when it was running yesterday shooting the cats, I could hear that clicking noise pretty loud. It is new. It sounds like it is coming from both sides and it is loud under there. But I can't really hear it from above. Could it be oil related? It sounded like it was right inside the drip pan but I know there's no moving parts in there. I wonder if it IS the lifters?

Thanks again Junk.

Actually the water Pump is Aluminum!!From under the car you will hear more ticks and noises!!There is a solid surface under it to bounce off of!!The oil pan is thinner than the rest of the engine and acts like a Resonator,Kinda like like the hollow body of a Flat Top guitar!!

 

[ZumZum]

Another question, when I had my head practically under the car when it was running yesterday shooting the cats, I could hear that clicking noise pretty loud. It is new. It sounds like it is coming from both sides and it is loud under there. But I can't really hear it from above. Could it be oil related? It sounded like it was right inside the drip pan but I know there's no moving parts in there. I wonder if it IS the lifters?

Probably your injectors clicking. No harm. Some years the injectors are noisier than others.

 

[Paul Higg]

LMAO! I guess you're right. That's why when I parked between two cars recently (on purpose), I usually park in the north 40, I heard the clicking bouncing off the other cars. I just wonder if this is normal because I never heard it before.

 

[Paul Higg]

Probably your injectors clicking. No harm. Some years the injectors are noisier than others.

Cool sig!

HAHAHAHHAHAHAHAHHAHHAHAHAHAHAHAHAHHHAHA

 

[ZumZum]

Cool sig!

HAHAHAHHAHAHAHAHHAHHAHAHAHAHAHAHAHHHAHA

thanks otfl