Foaming coolant under heavy load, bad head gasket?

[P.S.]

Perfect timing. This week's episode (published yesterday) deals with a possible cause of this- https://www.youtube.com/watch?v=ZTw_-uo5Yb0&t=646s

[Ordsgt]

I had the same problem. Under load it would foam up. Took the radiator cap off and watched the flow. Engine was at operating temperature. Saw coolant flowing. As I raised the rpm of the engine started to see small bubbles. Raised up RPM more and bubbles increased. Raised up RPM again and got foaming. Did compression test on engine and #2 and #3 were both down 10lbs. Pulled head and found blown gasket. Replaced gasket and no problems since (about 1500 miles) Have rechecked head torgue about 4 times and it is constant

[henryford30]

Hello
Many thanks to everyone for the answers. I have now ordered the Best B-6051-XO cylinder head gasket and the copper spray.
I will report back when I have removed the head.
@ Ordsgt
I have exactly the same symptoms, I hope it's the head gasket like yours !!!

[izze]

I had to come back to this thread just to say that switching to Sierra antifreeze fixed my foaming issue. I would always get foaming under heavy load. But I've now been on several long drives without any issue!

[BillCNC]

Running lean and/or running with the timing retarded will cause the engine to run hot. Could be the start of the issue.

Regards
Bill