Further inquiring as to the Cold Knocks

[acschilling]

Morning!

I have a question/ comment as to the knocks the 4.0 OHV makes when it cold. No matter the temp outside 20 degrees or 75 degrees my 92 OHV likes knocking on start-up. It'll go for a good 10-15 mins before it totally stops. I know about the lifters are needing to fill up with oil, but the only difference I have noticed in changing viscosity of oil is the position of the needle on the gauge on the dash. Was running 10w-40 before I changed to 5w-30. Needle was hanging low with the 40. My new curiosity with this issue is timing. The knock almost seems to change pitch while idling, will knock for 20-30 secs, stop for 5-10 secs, knock for another 20-30 secs, stop for 5-10 secs, then again; seeming to "loop" with its knocking while warming up. When the engine is warm/hot it idles so buttery smooth it scares me thinking the truck just died. Assuming oil flow is not an issue are there spark or timing issues that may be the culprit of the cold knock; bad sensor (IAC or TPS), plugs, computer, something of that sort? Thanks!

Fickle *****es

 

[darkriftoflife]

Is there a prior post about this? my 93 explorer does this to the point i bought a spare engine for when it blew up

I've dug pretty deep for the past couple months and haven't found anything

 

[Tbars4]

..I just had this happened on my 91 and knew I threw a rod..

Clean your idle air control valve (IAC) and see if it disapears..that is after knowing you have no stored codes..

 

[FR-425]

What Tbars meant is that he "thought" he had blown a rod,

but it turned out it was just the AIC causing it to diesel when cold.

Sarcasm just fails to translate in text. I gathered his thoughts with more clarity from reading his registry to see weather he blew the engine or not.

Found out, it was just the AIC..