HT4100 4.1, 4.5, 4.9 Discussion, My Car is Fixed!!! New Camshaft and Lifters in Cadillac Engine Technical Discussion; Hi all--
I just got my 85 Coupe Deville back today, outfitted with a new cam and all new lifters ...
I just got my 85 Coupe Deville back today, outfitted with a new cam and all new lifters and pushrods. It runs just great! So much more power. It also idles so smoothly I can barely tell it's even running.
6/16 lifters were BADLY worn--2 even had about an 1/8" gash in them.
3 lobes on the cam were pretty much flat. Another 6 or so were partially rounded off.
My distributor-drive gear (on the cam) was also badly worn.
This is just a reminder to check your oil frequently on this HT4100 motor! The guy I bought this car from drove around for a while with the "milkshake" oil after the intake gasket blew. This obviously did a lot of damage. My engine only has 35,000 miles on it.
Before I bought the car, the guy had a shop put in a new crank, bearings, and oil pump, but, for some reason, they neglected to put in a new cam.
very nice, maybe make a vid of the acceleration? My lifters make a little noise, nothing severe, but my 4100 goes like a rocket. Was your caddy sluggish, hesitant before like badly? My caddy shifts into second around 3000 rpms or higher, i put in a tranny from a 4.5 engine out of an 88 fleetwood.
make a video of the car
haha yeah, well i drive my caddy pretty hard at times, but usually i shift into second around 3000 rpms, and when i need to get onto the highway, i push it just over 3800 to get it into 3rd, and damn does this thing actually go pretty quick, unlike my 88 fleetwood with the 4.5 (it blew a headgasket mid summer), when i got it, it just didn't feel powerful on the road, only off the line. My caddy has a sports car feel to it, i dunno why but it does.
Camshaft and lifters i think break in within around 300 miles. And then again, i do my maintenance and use AMSoil 15w40 oil. When i was running 10w30 regular castrol oil, my lifters would collapse at times, and that is when i didn't drive it hard at all, i ran seafoam through the motor, then switched to my current oil, and no problems at all, i also upgraded to a 4.9 oil pump and oil pan. But also, i don't drive my caddy the way i drive my BMW.
Glad to hear the coupe is back in form. You're right about the previous repair being neglectful - if it was a dealer it was downright shameful. The milkshake oil always damages cam lobes and lifters first, then the crank and bearings.
I'm a little surprised to hear that your drive gear on the cam was badly worn with 35k. I've always heard the loading problem area was with the gear at the bottom of the distro. If I recall, you replaced that didn't you? Perhaps it was the slop in your old distro gear that wore out the cam gear. That combined with the lifter issues certainly contributed to your flat spot.
Anyway, drive proud. Most people wouldn't spend the $$ for such a repair on a 22 year old car, but we know better. That old girl will take you many miles now.
well i removed my cam, lifters all mint, cam is mint, dist gear all mint, engine super clean inside. BUT, cam bearing #1 spun and came out, i'm using old cam, replacing the one bearing and popping 16 new lifters in, and doing new timing chain and gears. Could've dropped a roller cam in there but no money for that.