let me try to make this short (as everyone knows how I like those long posts :) )

Anyway, a family friend owns a machine shop... he has an '87 DeVille.... HT4100, everything on that car was pretty much rebuilt... he also had a 1985 Fleetwood d'Elegance (first year of the smaller FWD cars) which also has the HT4100.... he has tore both of the engines down (rebuilt the one in his '87.... new heads in the '85) anyway, my father is doing a favor, and removing the engine from the '85 becuase it needs a new crank and cam..... either way I told him that he is wasting his time since that is one of the crappiest engines made in recent years... in any case... the owner of the machine shop was saying how the bottom end on the HT4100 is weak, and thus does not stand up to a beating.... well, not really a beating but they like to be babied and are not the enigne to drive around fast with.... ok understandable (well, the lack of power they have makes me think just how fast you could drive it...)

Anyway, when my father was talking with him, he was saying how the bottom ends are the same in the HT4100/4.5/4.9,,, which can't be since the cranks are different... now I never beat on my cars, I guess I live by my fathers words "don't baby it, but don't beat on it" I run them WOT now and then, but never do the plain stuid things that some of my friends do to their cars... but one thing that gets me is that my father kept saying for awhile... "you should go easy on it, the bottom end on these engines are weak" besides it getting annoying... I do not ever beat on the car... plus, I have never heard 1 case, of any of the 4.9 problems (not many) of anything about the bottom end on these engines... even after I tell him that, explain all the things that made the HT4100 crap, and how they fixed all that with the 4.5... and go through the whole long story of how the engine evolved and whatnot.... he still believes that the bottom end on the 4.9 is weak....

Is there anything to prove this otherwise? anyway I could convince him? it just gets annoying when there may be a slight noise in the engine (had a rattling sound.... although now we narrowed it down to the cat conv.) and the first thing he said was... it may be the bottom end, they are weak.....

welcome back... been on vacation or what?

The bottom end is still fine on my 1988 Eldorado with 200K miles. I just change the oil regularly and add the pellets to the coolant to keep the water out of the oil. I also rebuilt a 4.1 with 240K miles and the bottom end was still fine. Some engines that have weak bottom ends will develop cracks that originate from the outer main bearing bolt holes. Such engines I can think of include the GM 6.2 & 6.5L diesel engine.

as far as i know, the bottom ends on the HT engines were never the problems. even my old 4.1 still has a bottom end that is good. the main problems were on the 4100's which consist of intake and head gasket failure and in more isolated cases the oiling in the some 4.1's were considered less than great, causing the cam to warp prematurly. that is why cadillac opted to put a better oil pump into the 4.9's later on down the road. and just in case anyone would like to know, i know a guy who has a 94 deville with the 4.9 and 276,000 miles on it!!!:worship: just now needs to have some things on it replaced (which i will be paid for!), engine is not one of those things.

I havn't really been on vacation... few mini-tips (1-2 days) but just real busy and everytime I wanted to stop by, I kept saying to myself that I would be too long (I like to read alot of threads) then finally I just decided to check up on things...

my 4.9 has 91k miles... I run Mobil 1 in her (soon to be AMSoil) and when I remove the oil cover... there is not a single deposit of sludge or anything... it is super clean...

... my father says that when the engine has sat for awhile (oil drained back into the pan) that when I first start it, he can hear the rods moving around or something...... within a second, once oil has gotten around, the sound goes away (kinda like a very light rattling sound) he thinks it will be a good idea to pull the oil pan and tighten all the bolts on the rods and stuff.... I even told him that the HT4100/4.5/4.9 never had a problem with the bottom end, and the major deal with the HT4100 was the coolant and overheating issue... and just general lack of power...

I havn't really been on vacation... few mini-tips (1-2 days) but just real busy and everytime I wanted to stop by, I kept saying to myself that I would be too long (I like to read alot of threads) then finally I just decided to check up on things...

my 4.9 has 91k miles... I run Mobil 1 in her (soon to be AMSoil) and when I remove the oil cover... there is not a single deposit of sludge or anything... it is super clean...

... my father says that when the engine has sat for awhile (oil drained back into the pan) that when I first start it, he can hear the rods moving around or something...... within a second, once oil has gotten around, the sound goes away (kinda like a very light rattling sound) he thinks it will be a good idea to pull the oil pan and tighten all the bolts on the rods and stuff.... I even told him that the HT4100/4.5/4.9 never had a problem with the bottom end, and the major deal with the HT4100 was the coolant and overheating issue... and just general lack of power...
yeah, i would not worry about the bottom end unless you are going to some sort of forced induction or something. other than that, you have the right idea, just keep the oil clean and drive it like any other car, and you'll do just fine. but for me...:devil::lildevil::devil:...the 4.9 has some decent potential,:D (knock on wood!!!).

yeah, that's what I thought.. thanks for confirming it....

this car is my baby... I bought it with 78k miles last year.. now has 91k miles... at first I was going to limit the millage and stuff, so that in 30 years it would be low millage... but then I said... for what? a low number on the odo? honestly, I want, and love to drive the car, so I don't care about millage on it anymore... I will run synthetics and keep the maintenace up, she'll be young at heart... plus, once it gets past the "just an old car" area (like 180k miles) and into the "wow, lets see how long it'll go for" like 250k+ miles... it would actually be interesting.... even as it is now, everyone that sees the car has a hard time believing it is 11 years old and has 91k miles... except for some very slight blemishes and 1 door ding that only I know about, it looks new...

... of course I did get my Oldsmobile Eighty Eight as a winter car, and my Coupe was a Floridian car before I got it, so it has never, and will never see a winter.... hopefully I can afford to keep both cars on the road as the 88 is just one hell of a car in it's own right... mostly very cheap to maintain, and the relibility is just insane on it... plus it sat for 2 years before i got it, and has a rust problem (mostly underbody... body, besides paint is good) and while I am trying to fix some of the rust, it'll only get worse... at 121k miles, that car/engine has atleast another 100k miles before something expensive needs to be replaced (I am guessing tranny) in that case, I'll go to the local u-pull-it yards where they have about 20 similar year 88's, and they want $55 for a tranny.... that is definitly a great car....

... one thing I noticed... alot of my friends have 4bangers... one of my friends had a '98 Jetta.... 2.0 auto (fathers car, he was driving it) now he has a '94 Jetta (his car) 2.0, 5spd... the 5spd has more power (given) but he would always have to redline the 2.0 to get the car moving at any sort of fast rate.... I can go a while day without running my '93 DeVille full throttle... that includs pulling out fast, and even barking the tires from a stop.... so even if I do accelerate faster then someone with a smaller engine/car they are killing their engine as they overwork it and redline it, to get going just as fast as I am barley running 1/2 throttle on my car.... the same (but to a slightly lesser extent) goes for the 3800 V6.... both these engines have the low-end torque...

... OT... when I had my '79 Sedan DeVille on the road, I was driving aroudn with my friend... he wanted me to open it up a few times... now it has the stock, chocked 425 and the carb needs to be rebuilt.. I was getting on the thruway and was going about 40 around the turn, then floored it to get up to 75-80... at 40, she downshifted into 1st, then 2nd lasted all the way until I let off, and the first thing my friend said to me was.... omg, this thing accelerates alot faster then my car (he was driving the '98 auto at the time) I was like yeah, it's called low-end torque... you know, like on the VW commercial (joking with it).... then after that he coudln't believe the engine was "only" 180hp from 7.0L.... and said that it must have no power from a stop.... in which I proved that wrong by laying two strips of rubber a longer distance then his car could ever dream of even spinning the tires in the rain....

I run the Olds hard sometimes, but it is my knock-around car, the '79 is awaiting the enigne build, but the big block Cad is bullet proof and a little tire spinning isn't gonna do the slightest thing to that engine or tranny... I drive the '93 the easiest though.... on ALL of my cars I do regular oil changes and fix any problems that come up.... well, the '93 gets babbied that way, the Olds gets regular 99cent/quart Advance Auto oil (actually made by Havoline) and if the check engine light comes on for something small I just don't bother.... but we did fix and repalce alot of things on that.... the '79.... well, I bought it thinking it had a blown engine (that's what the guy told me) I drove it for 2 weeks and put 1k miles on it... did a basic tune-up, but it didn't need anything at all besides that....

...actually there are *alot* of little things both going wrong and already gone wrong on the '93 and it overwhelms me, then pisses me off, and makes it not fun to drive the car anymore, that is one of the reasons I want the Olds back on the road... so not only does it simply not have the things that have/are going wrong on the Cad, but I don't care if it isn't 100%, but I can drive that around, then when I get the desire to drive the '93, it will always be there for me....

BTW for pics of my car go here:

http://www.cardomain.com/id/night_wolf

I was in the middle of updating it, but never finished, and those pics are really old (last year old) go to page 5 for info on my Olds, and the '79 isn't even on it yet.... I need to spend some time getting that site nice again.

... my father says that when the engine has sat for awhile (oil drained back into the pan) that when I first start it, he can hear the rods moving around or something...... within a second, once oil has gotten around, the sound goes away (kinda like a very light rattling sound) he thinks it will be a good idea to pull the oil pan and tighten all the bolts on the rods and stuff.... I even told him that the HT4100/4.5/4.9 never had a problem with the bottom end, and the major deal with the HT4100 was the coolant and overheating issue... and just general lack of power...
You don't want to pull the oil pan and tighten anything. The rods and mains don't come loose but if they did there would be a heck of a lot more noise than what you describe. I would suspect you have a little piston slap which is perfectly normal and won't hurt a thing or maybe a little cold lifter noise. I sure wouldn't go looking for trouble.

Do some research on the amsoil before you change. IMHO you are already running the best oil you can get.

Steve B.

yeah, that's what I thought.. thanks for confirming it....

this car is my baby... I bought it with 78k miles last year.. now has 91k miles... at first I was going to limit the millage and stuff, so that in 30 years it would be low millage... but then I said... for what? a low number on the odo? honestly, I want, and love to drive the car, so I don't care about millage on it anymore... I will run synthetics and keep the maintenace up, she'll be young at heart... plus, once it gets past the "just an old car" area (like 180k miles) and into the "wow, lets see how long it'll go for" like 250k+ miles... it would actually be interesting.... even as it is now, everyone that sees the car has a hard time believing it is 11 years old and has 91k miles... except for some very slight blemishes and 1 door ding that only I know about, it looks new...

... of course I did get my Oldsmobile Eighty Eight as a winter car, and my Coupe was a Floridian car before I got it, so it has never, and will never see a winter.... hopefully I can afford to keep both cars on the road as the 88 is just one hell of a car in it's own right... mostly very cheap to maintain, and the relibility is just insane on it... plus it sat for 2 years before i got it, and has a rust problem (mostly underbody... body, besides paint is good) and while I am trying to fix some of the rust, it'll only get worse... at 121k miles, that car/engine has atleast another 100k miles before something expensive needs to be replaced (I am guessing tranny) in that case, I'll go to the local u-pull-it yards where they have about 20 similar year 88's, and they want $55 for a tranny.... that is definitly a great car....

... one thing I noticed... alot of my friends have 4bangers... one of my friends had a '98 Jetta.... 2.0 auto (fathers car, he was driving it) now he has a '94 Jetta (his car) 2.0, 5spd... the 5spd has more power (given) but he would always have to redline the 2.0 to get the car moving at any sort of fast rate.... I can go a while day without running my '93 DeVille full throttle... that includs pulling out fast, and even barking the tires from a stop.... so even if I do accelerate faster then someone with a smaller engine/car they are killing their engine as they overwork it and redline it, to get going just as fast as I am barley running 1/2 throttle on my car.... the same (but to a slightly lesser extent) goes for the 3800 V6.... both these engines have the low-end torque...

... OT... when I had my '79 Sedan DeVille on the road, I was driving aroudn with my friend... he wanted me to open it up a few times... now it has the stock, chocked 425 and the carb needs to be rebuilt.. I was getting on the thruway and was going about 40 around the turn, then floored it to get up to 75-80... at 40, she downshifted into 1st, then 2nd lasted all the way until I let off, and the first thing my friend said to me was.... omg, this thing accelerates alot faster then my car (he was driving the '98 auto at the time) I was like yeah, it's called low-end torque... you know, like on the VW commercial (joking with it).... then after that he coudln't believe the engine was "only" 180hp from 7.0L.... and said that it must have no power from a stop.... in which I proved that wrong by laying two strips of rubber a longer distance then his car could ever dream of even spinning the tires in the rain....

I run the Olds hard sometimes, but it is my knock-around car, the '79 is awaiting the enigne build, but the big block Cad is bullet proof and a little tire spinning isn't gonna do the slightest thing to that engine or tranny... I drive the '93 the easiest though.... on ALL of my cars I do regular oil changes and fix any problems that come up.... well, the '93 gets babbied that way, the Olds gets regular 99cent/quart Advance Auto oil (actually made by Havoline) and if the check engine light comes on for something small I just don't bother.... but we did fix and repalce alot of things on that.... the '79.... well, I bought it thinking it had a blown engine (that's what the guy told me) I drove it for 2 weeks and put 1k miles on it... did a basic tune-up, but it didn't need anything at all besides that....

...actually there are *alot* of little things both going wrong and already gone wrong on the '93 and it overwhelms me, then pisses me off, and makes it not fun to drive the car anymore, that is one of the reasons I want the Olds back on the road... so not only does it simply not have the things that have/are going wrong on the Cad, but I don't care if it isn't 100%, but I can drive that around, then when I get the desire to drive the '93, it will always be there for me....

BTW for pics of my car go here:

http://www.cardomain.com/id/night_wolf

I was in the middle of updating it, but never finished, and those pics are really old (last year old) go to page 5 for info on my Olds, and the '79 isn't even on it yet.... I need to spend some time getting that site nice again.


whew have we missed those posts... :holycrap: just kidding :coolgleam

If you're running synthetic oil & it's been sitting awhile, that stuff just keeps flowing & the lifters bleed down. In my LS6 the lifter noise goes away in about a second, the piston slap takes a couple minutes to quiet down.

this is my dailey driver.... at least for the next month, then with the new insurance plan, hopefully I'll get the Olds on the road... basically, it is not a matter of the car sitting too long...

...my father and I were talking about it again today.... he was saying that back when he was 16 and did oil changes, the tolerances on engines was greater (?) then today, so when it would first start there would be piston slap until oil got into the crank on rod bearings.... and that the same noise he hears when I do a cold start on my engine is the same noise he used to hear.... he said that we could pull the pan (if it is as easy as the HT4100 he is working on right now) put new bearings on the rods and put a new oil pump in it.... but again today, he said that the owner of the machine shop heard from his suppliers that the bottom end on the HT4100 are very weak, and that the HT4100 and 4.9 are smae design, therefor the bottom end on the 4.9 is weak...on the HT4100 my father is working on.. it didn't spin a bearing, but the notch that holds the bearing in place broke, so the bearing is spinning on the crank....

... since I got the car last year with 79,917 miles on it, I switched her to Mobil 1 10W-30 with AC Delco filter.... my father is now an AMSoil dealer, so I can get AMSoil for the same price as I was paying for Mobil 1.... I would be interested to hear about comparison, and why Mobil 1 may be better then AMSoil...

... the first 2 oil changes I went 5k miles b/w.... then I started reading more and more that synthetic oil can last much longer, so I have decided to run the oil life meter down to 0 and see where it is (I have the millage wirtten down in the cars' log book) then when it gets to 0, I will see how many miles it is, and decide to change the oil, or simply change the filter and top it off... I check the oil level all the time, and always keep a quart of oil with the car so it is always topped off....

on the '79 I did an oil change when I first got it, although the guy did a recent oil change on it, I asked him what oil he used, and he said 10w-40... I read that the big block Cads don't take well, so I was just gonna get cheap regular oil, but my father told me to use his Castrol SynTec (what he swore by and used in all his cars and trucks before he became AMSoil dealer) <--- many times I tried to get him away from the SynTec, and switch to Mobil 1, but it didn't work.... anyway, I just had to buy the filter, and I figured the Syntec is better then 99cent oil, so I used it.. next oil change I don't think I will use Mobil 1 on the 425 (if I even decide to keep the 425 in there) becuase in the valve cover and on the oil cap, there is sludge, and I heard that on an older, high millage engine (well, only 85k miles) synthetic can actually break free deposits and block small passages....

On the Olds I use 99cent/quart Advance Auto 10w-30 (I was told it is actually made by Havoline) and all my cars get AC Delco filters... on the Olds I went 4k miles b/w oil changes... it was my winter car, so the engine was cold often... I will probably go 4-5k miles on that.... also, no matter what car I drive, I always check the oil level and keep it topped off.... no point in running good oil if you don't check it, then ruin your engine by running it out of oil...

i still would'nt sweat over the bottom end streangth of the 4.9, i have worked many of the 4.x series, and no big issues came up with the bottom ends unless someone took no care of the car at all, but i will garantee that will hold true for any car, even a benz or bimmer that is new. bottom line is, if you dont take care of the car (oil changes, filter and tune up), then yes, your car will not last as long as a car that has been cared for. i have also flogged my old 4.1 many of times (dont know why, has no power!!!), and the thing still has a bottom end, just blew the rear main oil seal on her:annoyed:...but take my word for it,give that good'ol 4.9 some carbon cleaning on the highway, or from a stop, and as long as you dont over do it, you will be just fine.:lildevil:. also, check my site out for the white deville, that has a 2-peice block (blown), but the oil that was left in her was coffee!!!!!!!in other words, someone neglected her for a long long time, and she blew!!! but if you take care of the 4.x, you will be fine.