: 05 STS V8 Northstar oil leaks

12-20-11, 12:42 AM
hey gang, have 05 sts northstar with 42k and the cam seals are leaking oil around the sensors and mechanic says all northstars leak. they want 2100 dollars to fix. i am concerned with all this intrusion into the motor. any suggestions?


12-24-11, 11:02 AM
Well, my 2005 STS with the N* does not leak a single drop and I'm just coming up on 100K miles...I think the mechanic is making a general statement considering that oil leaks were common on the FWD N* engines (case half leaks).

12-24-11, 10:49 PM
My 2006 has 72,000 & doesn't leak a drop. It might burn an oz. every few months. I have reason to believe it was 'broken in' by a car lover.

My wife's 2007 STS spent its first year as a rental and was likely driven hard. It burns a bit but doesn't leak. It now has about 55,000 miles.

Opinions vary.

12-25-11, 12:01 AM
Oil leaks through the cam sensors on my V too. It doesn't leak on to the ground, just enough to make the sensors wet. I am not worried about it.

12-28-11, 12:27 PM
Your car isn't leaking too much oil until you can't get enough in it that you run out before you get to where you want to go.

12-28-11, 07:14 PM
Had a 2000 N STS and now an 05. Neither leaked although the 00 used a qt between changes. The 05 uses no oil and no leaks.

12-28-11, 07:53 PM
i had a few leaks valve covers oil pan front timing cover and rear cover
all covered under my extended warranty (paid 700 for it the front magnetic shocks alone at 1500 covered that)

12-29-11, 12:55 PM
checked with other mechanics and all said that northstars are notorious for oil leaks. just wondering if i get it fix, will same thing happen in another 40k.

12-29-11, 05:37 PM
Only the Northstars with leaks go to the people who fix Northstar leaks; therefore all the Northstars they see leak.

01-02-12, 12:05 AM
149k. 10 years. Maybe its a miracle but I'm leak-free.
But that isn't to say that they don't or can't.

What's involved that requires $2100 of service? Engine removal?

01-08-12, 11:11 AM
replacing front seals and gaskets and valve cover gaskets and cam seals o rings.

04-07-12, 10:10 PM
replacing front seals and gaskets and valve cover gaskets and cam seals o rings.

How much is this going to cost you.?

04-08-12, 11:48 AM
Well...thats pretty low miles for an 05. What I will say from my experience is that when cars sit and dont get driven, things dry out...I've seen 2 of my grandfathers lexus ES350 leak because the import guy who fixed the leaks said "its better to drive the cars than let them sit, cause stuff will just dry out" just my input....obviously we all want as few miles as possible, but cars that dont get driven tend to have this kinda stuff happe(not saying you dont drive it)...mine has 105k, and not a drop. IF its just covers and gaskets, im pretty sure you can find a reputable mechanic who is capable and far more reasonable. I agree with the other guy who said the older FWD had leak issues sometimes, I have heard that...but ive talked to a few mechanics and from what I can tell the 05 and beyond N* dont have too many issues with oil leaks.

04-08-12, 11:54 AM
Mine has 50578

04-09-12, 08:04 AM
Ya...obviously its kinda good/bad luck kinda thing....Could be also when the engine was put together things werent torqued exactly how they should of been ...maybe they started using different gaskets on 06 07 etc because 05's might of had some issues...but I think its just a matter of luck...I know 3 people at my office who have had 02,03,03 sts's and none of them have had the head gasket issues....not to mention on of the guys just sold his with 215k ...and the car was not taken care of at all...but he said it didnt leak at all. I have to believe you can find someone who knows engines and can replace for much cheaper...not to mention I wouldnt think it would happen again in 40k. I always take my car to the dealer for something techinical for sure...but any good mechanic who actually works on engines(not just brakes,shicks..etc) can replace gaskets etc...and probably way cheaper...parts probably arent expensive at all.

04-09-12, 08:21 AM
I just got mines back from the dealer last week for an oil leak . They replaced (oil manifold lower crankcase seals). $2900.With only 74k miles.

04-15-12, 08:18 AM
Dont ask me why,but I was thinking about your CAM issue.....and I always look for TSB's about twice a year. There are 2 TSB's for the CAM sensors/and or CAM actuators in the STS....some from movement or inproper seals. If you google TSB and go in the NHSTB(or whatever the heck it is) you may just be ablke to get this taken care of.

04-15-12, 08:29 AM
Mines in the shop again for this. Oil fouling out the cam sensors due to bad actuator seals.

07-02-14, 12:05 PM
Any chance it is being covered by Gm for a recall since there is a Tsb for the cam sensor?

07-02-14, 01:15 PM
Recalls are for safety items. PITA items out of warranty are on the owner.

07-02-14, 01:25 PM
Looks like the thread died over 2 years ago.

Never did hear of a recall.

07-04-14, 02:14 PM
I found out that my camshaft position actuator oil control valves need replacing be cause they are leaking through the electrical connection at the front of the engine. Do I need to replace the actuators themselves (the circular actuator with teeth that need to be properly aligned) or can I get away with just replacing the oil control valve?

07-04-14, 04:47 PM
My Northstar engine with 125,000 miles pukes oil out until it drops 1/2 to maybe 1 quart down. Appears to leak from the crankshaft seal and the separator plate.
I put cardboard under it when parked inside my garage.
It's a build result from the Roger Smith era.
That's the reason my normal daily driver as well my wife's car are Toyota products.

07-05-14, 10:25 AM
Is it safe to drive with those leaks? Can I do more damage or just keep up on oil levels?

07-05-14, 10:34 AM
Keep the oil at the proper levels and it'll be fine.

07-09-14, 09:27 PM
The redesign for the XLR/SRX/STS fixed the old N* ills.

07-09-14, 09:35 PM
The redesign for the XLR/SRX/STS fixed the old N* ills.

Aka the LH2 and LC3 vs the old LD9 and L37

07-10-14, 12:19 PM
My Northstar seeps some oil at the seams and I add two quarts every 2500 miles. I never did anything about it and the engine is all original and at 203,000 miles runs great.