Mac113

Does anyone know what the normal Cylinder Head Temperature should be?? I'm running anywhere from 208 - 212 degrees and a little nervous because I think I have a clogged cat.

f150doitpruitt

Normal range is 195-210 I wouldn't worry about it too much. But you can always check your cat temp too just to be safe.

Mac113

Thankyou for the help! I was just cruising down the highway at about 80mph and it was hitting 218-220 degrees. Is that something I should worry about or? Also I'm going to pick up a temperature gun later. What is a normal temp the cats should be?

Thanks again and much appreciated!
Mac

2008__XL

My scanguage reads 188° - 192° on hot days and between 178° to 182° in the cold winter months for cylinder head temps. The highest reading I've ever seen was 196° and that was as the truck was warming up on a hot day right before the coolant started cycling. It quickly went down.

I think your readings may be coolant temp and not the actual cylinder head temps. If they are, they're definitely higher than mine.

My scanguage always shows a slightly higher coolant temp than CHT.

f150doitpruitt

If anything I would put a new motorcraft thermostat in it just to be safe. I don't see it being a catalytic problem. Are you getting a CEL?

Mac113

I'm getting a cel for catalytic bank 1 but I thought it was due to my magnaflow high flow cats. When we welded the bungs in we didn't weld them half way in/half way out, we welded them on top. But now that my Edge is saying my cylinder head temperature is 220 I'm getting a bit nervous lol

2008__XL

Unless you're towing a trailer up a steep grade, it shouldn't be running that hot.

F150Torqued

@Mac113
You raise an interesting question. The rather wide range of responses you got - and having numerous log files of CHT readings taken with my Torque Pro App, sent this highly curious ole man off searching for more knowledge.


FWIW. Here is what I found:


What is "NORMAL" is relative to engine type. They are NOT all the same by several degrees. The Motorcraft Diagnostics Reference Chart for the 5.4L 3v (like yours and mine) indicates 201 to 207ºF. Yours (and mine) is generally within normal (certainly within margin of error for scanner readings). Mine seems to run 206-7 up to 220. I'm running a 195º thermostat and ECT runs almost exactly that. It seems normal to me that the Cyl Head metal - where the CHT is located (between cyl 2-3) - would run slightly hotter.


I am attaching the Diagnostic Reference Chart for our engine to confirm my findings. I have found this chart helpful on many occasions.
Also, my Motorcraft OBDII System Operation Summary for Gasoline Engines (at page 62 of 98) indicates "For P1299, MIL illuminates immediately if CHT > 270º and alternate cylinder Fuel shut-off (Limp MODE) is activated to reduce engine and coolant temperature. So we're definitely on the safe side! LOL

ALSO INTERESTING: My Torque log files (and live test today) confirms Variable Valve Timing (EGR) effect definitely cools combustion temperatures. (imagine that) I notice when Cam Retard is very high, I see CHT decline several degrees. Conversely, when variable CAMS are advanced, I see CHT increase. Going up long grade (keeping CAM retard at Zero retard - Full Advance), mine went up to 239º - Per Torque Pro.


Hope this helps. I learned something from it. Thanks.