Hello all. I've posted a few questions about my vehicle before but this one's a bit more specific. It's a 1991 Ford Explorer with the 4.0 OHV Cologne engine. Notorious engine for top end valvetrain noise due to lack of lubrication. Long story short, I went in to replace the lower intake gasket and while I was there, replaced the pushrods & rocker arms as well as rotated the rocker arm shafts. I found quite a few unhappy wear areas but not as severe as I thought. I didn't see any obviously collapsed lifters either. I was hoping that might cure my long-time cold-only ticking issue. It didn't.
So, I'm thinking that the hydraulic roller lifters aren't getting enough oil when cold, probably due to varnish or clogging (there were extended oil changes in it's past). The issue is only when cold. When it's warm, it's all dead silent. When starting it cold, it's quiet for 5-10 seconds then starts rattling away until it warms up.
My question is, being that the heads have to come off to replace the lifters, is there anything else I should try as far as high-detergent oils or snake oils? I've got Mobil 1 HM Syn 5w30 in it right now, just because it was on sale.
So, I'm thinking that the hydraulic roller lifters aren't getting enough oil when cold, probably due to varnish or clogging (there were extended oil changes in it's past). The issue is only when cold. When it's warm, it's all dead silent. When starting it cold, it's quiet for 5-10 seconds then starts rattling away until it warms up.
My question is, being that the heads have to come off to replace the lifters, is there anything else I should try as far as high-detergent oils or snake oils? I've got Mobil 1 HM Syn 5w30 in it right now, just because it was on sale.