My colleague is selling her 85 Seville with the 4.1 engine. The car has 72K on it and seems to be in good condition overall ...serviced regularly, drives well, etc. Would you trust the engine in this car? What other areas should a potential buyer look for/be aware of?

 

The HT4100 (4.1) was introduced around 1982 and slowly morphed into the NorthStar in the decade folowing. Just as with the N*, maintenance is everything. It is not a powerhouse (~130HP), but the Seville is not a battleship either.

The '80s wasn't GM's best, and many considers the HT4100 a flop that was hastily put together and shoved into bodies built for larger engines to hurriedly comply with gub'mint regulations, similarly to the innovative but troublesome variable displacement 368ci, and the diesels.

The car in question has been on the road for over 20 years, which itself is proof that it has been maintained well (of course, if it still has the original, unmolested engine). Another plus is, in this case, that you know and trust(?) the owner who knows(?) the car's history.

If you like the car and want (need, can afford) it, this is the one to get.

 

adding to that, the '85 4100-std was an improved version from the early 4100 engines.

the 4100-std engine is good for 300,000+ miles .. plenty of cars out there hitting that mark now.
several at the 400,000.

alll the 4100 engines, as the 4500 and the 4600 engines, are susceptible to headgasket
damage if the coolants were not maintaned religiously. IMO, the day you get it,
play it safe, dump/drain the coolant in it and re-fill with a 50/50 mix of Prestone and distilled water.
add a couple of tubes of supplement (Bar's LEAK - GOLDEN ) .. $0.90 at Big-Lots.

i tag it 4100-std because there is a difference between that standard 4100 and the 4100-Allanté,
different itnernals and about 40 hp ..


the SUPPLEMENT -

this is the same stuff as the pellets below .. look for the words "GOLD" or "golden seal"
the packages change often, but the GOLD or GOLDEN SEAL labels remain.
both this one and the pellets are organic, ground GINGER -
these are NOT METALLIC POWDER which i strongly advice against.

DOSAGE - One Tube Treats Cooling Systems up to 2 Gallons



this is what GM puts in the engines at the factory,
in fact GM buys it from this company:

DOSAGE - TWO pellets per Gallon



"Bar's Leaks Cooling Radiator Stop Leak & Conditioner tablets inhibit the formation or rust and scale, neutralize pH imbalance, controls electrolysis, lubricates and seals internal, external and coolant-to-oil leaks.

These are the same tablets as used by many OEM auto and truck manufacturers. Bar's Leaks Cooling Radiator Stop Leak & Conditioner is designed to enhance the use of antifreeze or can also be used in water. When used in water alone, it is also recommended to use a cooling system anti-rust and water pump lube.

Bar's Leaks Radiator Stop Leak Tablets are compatible with ALL brands of antifreeze including conventional green or blue (silicate-based) and extended life red/orange or yellow (OAT/HOAT) coolant. For most vehicles leaks stop in only a few minutes."