: How long do Northstar engines last?



RoadTrekker
11-11-07, 03:07 PM
I've got a 99 Deville with 71k miles on it. The dealer wants $3000 to fix an oil leak between the pan and lower crankcase.

Is it worth it to fix it?

How long can I expect the engine to last?

JN in CA
11-11-07, 04:13 PM
RoadTrekker, you asked essentially the same question twice.

Let me do the cheap thing and refer to a great answer posted in this thread: http://cadillacforums.com/forums/northstar-performance-technical-discussion/5919-4-6-northstar-engine-trans-swap.html

Ranger
11-11-07, 07:22 PM
We have had people with over 300K on a well maintained Northstar.

RoadTrekker
11-11-07, 10:39 PM
Ranger, There are always statistical outliers. So how rare is, say, 150k miles or 200k miles?

I've noticed when looking at used cars for sale on big web sites that I see a lot of high mileage Town Cars but rarely Devilles. Partly that's because Town Cars are heavily used in livery and as taxis. But then that leads to the question of why that is. I've asked Town Car taxi drivers and they say the Town Car engines last longer.

I'd like to get a sense how long one should go along willing to do major repairs to a Deville. So far the engine seems like the big issue.

Ranger
11-11-07, 11:25 PM
150-200K is rather common. Several here alone. They are known for head gasket problem. Especially pre 2000's. Some seem to run forever and some don't. Cooling system maintenance is a big factor. This thread may be of some help.
http://www.cadillacforums.com/forums/northstar-performance-technical-discussion/3521-high-mileage-northstar-thread-who-can.html

Jesda
11-11-07, 11:33 PM
Its a tough call. Some have blown head gaskets as early as 50k, and some have gone 250k+.

Its a question thats somewhat hard to answer. Of course, a motor with a properly repaired HG will keep going. The internal mechanicals will probably last 'forever'. Its everything else that usually fails.

JN in CA
11-12-07, 01:15 AM
Its a question thats somewhat hard to answer. Of course, a motor with a properly repaired HG will keep going. The internal mechanicals will probably last 'forever'. Its everything else that usually fails.

That's what the N* engineers say, but that begs the question: if the internals (bearings, rings, rods) outlast the car, then why are there threads on here by people who rebuilt (or are rebuilding) their engines?

These threads can't all be people who were in accidents, or ran the engine w/o oil. Are these rebuilds just flat out unnecessary overkill by DIYers?

Ranger
11-12-07, 02:37 AM
The weak link is the head gaskets. Everything else will outlast the car.

Cadillacboy
11-12-07, 12:39 PM
I think w/ a good maintenance it should last longer than 150 K miles .