Slight knocking when cold - ZR-1 Net Registry Forums

Subfixer · 12-13-2018

It's been fairly cold up here lately, 20-30 degrees.
My 92 has a knock for a while at startup until it gets up to normal water temp and normal oil temp. More pronounced while under load.
Oil pressure is normal and not fluctuating, about 70 psi.
Sounds like only one cylinder, not like the cold piston slap in my 5.3 Suburban.
Once everything is warmed up, the knock goes away. Gets quieter as the temps come up.
Car has 18,900 miles on it.
So, is this normal, or should I be checking rod bearings?

12-13-2018	#1
Subfixer Join Date: Sep 2018 Location: Groton, CT Posts: 384	Slight knocking when cold It's been fairly cold up here lately, 20-30 degrees. My 92 has a knock for a while at startup until it gets up to normal water temp and normal oil temp. More pronounced while under load. Oil pressure is normal and not fluctuating, about 70 psi. Sounds like only one cylinder, not like the cold piston slap in my 5.3 Suburban. Once everything is warmed up, the knock goes away. Gets quieter as the temps come up. Car has 18,900 miles on it. So, is this normal, or should I be checking rod bearings? __________________ 1992 ZR1 #442, 2 tops, White, White, Haibeck 415, 3.90 gear, Coilovers 2018 Audi RS5, 2.9 V6 Twin Turbo, Auto, Black, Black 2021 Audi Q3, 2.0T, 8 spd Tiptronic, Navarro Blue metallic, Pearl Beige