[DOHC-Termi]

Have a terminator with very low miles (5000) that has an odd issue. The engine starts ticking at 210F coolant temp (normal operating temp), and only at idle. No tick is heard on cold start, but once the car reaches 210F coolant temp you can hear the tick start, but again only at idle. Give it a little gas to reach 1000 rpm, and the tick noise is gone. Gotta stick my ear down by the passenger side fender well to hear it. Noise is not heard inside the cabin of the car. Sounds like tick tick tick, tick tick tick, tick tick tick, tick tick. Then it repeats over and over again the same way.

Taking her out for a 30 minute drive, and then doing the following...

Running the engine at 3500 rpm for 3 minutes @ idle, and getting the coolant temp up 230F makes the noise temporarily go away. The coolant temp can cool all the way back down to 210F after the 3 minute run, and kick the fan off, and I won't be able to hear the tick. But let it cycle the fan a few more times to cool things down more, and the tick will return.

What is the issue here? Thanks.

 

[eschaider]

A 230˚F coolant temp is on the hot side. Your engine will appreciate a lower coolant temp.

How long have you owned the car? These engines had a head tick that was associated with mechanical problems on the driverside head. When the cars were still in warranty this was a warrantiable issue. Warranties have run out a long time ago so this one is going to be on you.

Here are a few screenshots from Ford's Mustang service manual speaking to ticking issues;

The manual is over 4000 pages long so it is not possible to post or send it to you through the website. If you want it, send me your email address and I will email it to you.

 

[DOHC-Termi]

Yes, I know 230F is getting close to the danger zone. It was simply a test to see if higher temps would help make the noise go away... which it did. I’ve owned the car since February of 2021. Lifter/Lash adjusters aren’t the issue as I had them replaced. A piston issue sounds like the likely cause as they do expand when getting hot. It’s just odd that I have to get the car up to 230F on the coolant temp to make the noise go away.

 

[eschaider]

The noise abatemetn with increased engine temp confounds me also. I have difficulty explaining it.