: ht 4100 rwd (1985 fleetwood brougham)



tonloc
09-04-08, 09:06 PM
I Have a 1985 fleetwood brougham that has an HT4100
it went throug the gasket ordeal and to make a long story short
I want to either replace it with a better motor or just order a remanufactured
engine of the same that is currently in the car (ht4100).
I don't want to get rid of my car because its practicly new otherwise.
I'm looking for some enlightment to help me decide what to do.
I will be doing this project my self and I'm not very experienced mechanic
and am not too familiar with the mechanic lingo. I have one other project
under my belt.how ever it was alot easier than this one.
so this is actualy my second project as you can see I'm a novice but I
have alot of common sence .
my question is as follows: which is my best recomended course of action?
should i keep the same type of motor or is there some other options
that would not be so problematic for a brand nubian like myself.
any input is greatly apreciated
Thanks again !
:halo::halo:

jayoldschool
09-04-08, 09:53 PM
Can you describe exactly what is wrong with your engine? We can probably help you through it.

A reman 4100 is $3057 from Jasper.

dirt_cheap_fleetwood
09-05-08, 11:36 AM
A reman 4100 is $3057 from Jasper.

That or just drop a 305 in there. Personally I would stick with the 4100 because I would rather have it stock and with any other engine your Fuel Data Center will no longer be accurate or may not work at all.

tonloc
09-05-08, 01:53 PM
Can you describe exactly what is wrong with your engine? We can probably help you through it.

A reman 4100 is $3057 from Jasper.

when the whole problem first ocured my car overheated . so I pulled over,
looked under the hood thinking a hose busted ,however I colund't find the source of the steam . I then removed the aircleaner cover from the housing
and noticed that there was antifreeze inside the housing along with my air filter. I let the car cool off for a few minutes then proceeded to drive the rest
of the way home (1.5 miles aprox.)my car was running very rough and was acting like it was gonna turn off.whe i finally got home i let it cool off,
went back checked the oil.and on the dipstick was something that looked like
peanutbutter just not as thick. I'm assuming that it was a mixture of oil and antifreeze.so I changed the oil and started it . and yes, it was still overheating. I then drained the oil again,drained the antifreeze and then put new oil just so that mixture wouldn't sit in the pan. I then began asking around and listened to many very different theories and opinions .
then a friend suggested we try the intake gasket wich was a nightmare
just removing the distributor because of the bolt or nut that holds it down
sits underneath the distrbutor and it was almost impossible to get to but after
a good strugle we managed. wich i found out an easier way to do this from reading the forums. but anyway we put new gasket set . then it was another nightmare because we had a leak from the upper thermostat housing it has a seal and slides into the intake. we still have this leak and the car still overheats. but because my car makes a certain noise when I start it wich it did't used to before the problem occured a couple people have said that my bearings are bad and that my motor woulnd't last very long .
my car starts but its not drivable the noise it makes is like a "clunk" but only
when I start it then it smoothens out.
I have read the forums and most people agree that a change of this very problematic engine would be in my best iterest in order to avoid the same type of problems further down the road.this HT4100 requires more frequent
oilchanges and antifreeze changes as well as those antifreeze supplement
tablets wich I did't know anything about. and as far as I know those darn tablets might have been the whole cause of my cadillac's downfall.
I don't want to get rid of my car because it has only 47k original miles
it was sitting in someones garage for a long time it practicly new it even
has the plastick chrome protectors that come with it when you buy it brandnew.no one sat in the back seat.
my plan is to fix it and keep it for myself so I want to do it right.
I'm a person that enjoys very much learning from others . I have very little
experience but I'm not afraid to get my hands dirty. I like to be well informed
and the internet has been a very valuable resource for me .
I ask for any help or advice that you can give .
and thank you for taking the time to read my very long post
I try to be detailed in order to save time . Again Than You !!!
Ton Loc

adiaz2k
09-05-08, 05:08 PM
I've got that same motor in my 84 coupe and I plan on replacing it with a different motor to avoid the same issue.

jayoldschool
09-05-08, 05:55 PM
I would guess that when you overheated it, you blew a headgasket, not an intake gasket. This allowed the coolant into the oil (making the peanut butter milkshake), and eventually caused one of the rod bearings to fail.

Rebuilding a 4100 is going to be no more difficult than any other V8. Disassemble, inspect, turn undersized damaged crank areas, bore, re-ring, new bearings, etc, etc. Go visit some local machine shops and ask lots of questions. You may be able to get it rebuilt for less than a reman engine. There are lots of options out there other than Jasper, btw. Stop by your local Advance Auto Parts - they sell cheap rebuilds too.

You could put a used engine in, but why bother? Without the history, you will be installing someone else's problems.

There isn't really a direct "replacement" engine for the 4100 (other than another 4100). Yes, you can use any GM V8, but they all will require work. Mounts, wiring, fuel delivery... the list goes on and on. To make matters worse, the 4100 cars got lighter duty drivetrains than the earlier big block cars (425/368) and the later Chev 5.7 cars. Namely, the weak 7.5 rear end. That rear is not a great choice in a heavy car with an engine that makes any kind of serious torque. The 425/368 cars got the very heavy duty GM "P" axle, while the later 5.7 cars got the GM "corporate" 8.5 (as found in pick ups, Impala SS, cop cars, etc).

So... my advice? Rebuild yours, or buy a reman 4100 and replace.

dirt_cheap_fleetwood
09-06-08, 12:44 PM
I've got that same motor in my 84 coupe and I plan on replacing it with a different motor to avoid the same issue.

A rebuilt one will be very unlikely to have any more problems, especially if it is taken care of the way it should be from day one. Frequent coolant changes with the Barstop additive and stuff.

Aron9000
09-06-08, 06:37 PM
I'd throw in a built 350 Chevy V8 with a carb. You can build them or get a crate motor for less than the price of a new 4100 V8. It'll make a lot more power than the 4100 and be a lot more reliable. If you want a fuel injected motor, the 5.3 V8 from a wrecked Chevy truck/tahoe can be had for under $1500, including motor and trans.

Also, the 7.5 axle will work fine provided that:
You aren't making more than 300rwhp, and you aren't going to the dragstrip, doing hard launches with sticky tires. They put this same axle in a the LS1 powered fbody, which has around 300rwhp stock.

dirt_cheap_fleetwood
09-07-08, 10:55 PM
I like the idea of the 5.3 Aron, but I don't even think you need the tranny, just the engine. If I remember correctly these had the 700r4, which is also what they used in the F bodies and the S-10 trucks, so its plenty strong.

jayoldschool
09-07-08, 11:03 PM
Actually, the 4100 cars got the 200-4R. It is not a strong trans in stock form. It CAN be built strong (just ask the Buick GN guys). While it does have a dual BOP/Chev bolt pattern, it won't bolt to the new LSx style blocks like the 5.3.

A swap like the 5.7 is easy to talk about, but it in reality is a major undertaking. Mounts, wiring, computer interface for the mileage and HVAC, etc..

Aron9000
09-08-08, 06:12 AM
Actually, the 4100 cars got the 200-4R. It is not a strong trans in stock form. It CAN be built strong (just ask the Buick GN guys). While it does have a dual BOP/Chev bolt pattern, it won't bolt to the new LSx style blocks like the 5.3.

A swap like the 5.7 is easy to talk about, but it in reality is a major undertaking. Mounts, wiring, computer interface for the mileage and HVAC, etc..

With the late model 5.3 V8, the trans is electronically controlled as well, that's another reason I'd just do both the engine and trans at the same time.

The 350 swap wouldn't be too bad if you had a junker 90-92 Brougham that came with a 350 to pull parts off of/use for reference. Hell, you could even yank that bigger axle while you're at it.