I finally got around to replacing the starter on my '07 Northstar CXS. It's under the
intake manifold, along with the knock sensor. It's the worst starter I ever replaced, but the job is not impossible. (Certainly MUCH easier than replacing the alternator on the same engine.) It took me the better part of a day to do it, but I take a lot of breaks and double check what I'm doing along the way, double check torque specs, etc. There are also a number of youtube videos that can help, as there are a lot of
Cadillacs out there with various versions of this same engine.
First of all, I DON'T fault the engineers for putting the starter under the
intake manifold. On the contrary, anybody who has worked on this engine in the Buick engine compartment should appreciate the engineering that went into cramming all that engine in there.
Another positive aspect of this job is that you don't have to jack up the car and get under it to replace the starter. Everything is done from the top. A lot of bending is involved, but it is not a serious back-breaker.
So here is the parts list I bought for this job:
GM Professional starter $153 from Rock Auto 3371132 (337-1132)
Air
intake gasket set $21 ebay Engine
Intake Manifold Gasket Set DNJ IG3164
Fel-Pro ES70599 Fuel Injector Seal Kit $8 ebay
ACDelco 213-1576 Knock Sensor ebay $12
Fuel line removal tool $15 ebay Lisle Tools 39400 6 Piece Angled Disconnect Tool Set
About 4 cans of
intake cleaner from walmart at $3 a can
I do have one other confession to make. I originally bought a $65 discount Chinese starter off ebay, but later changed my mind after I found a new AC Delco for $153 at Rock Auto, with no core charge. No way do I want to change that starter again, I reasoned, so I bought the best I could find. I had to pay $22 to send the discount starter back, and on top of that they charged me a 20% restock fee. So, I lost more than half my money on that deal, but feel content with the new AC delco starter. Throw in all the disposable mechanic's gloves and such, and I came out of this job spending less than $270. That's considerably less than the $387 retail price of just the starter, which any mechanic will charge you, plus labor. Standard labor charge on this job is 1.6 hours, which might be possible if you really know what you are doing and have everything needed at your fingertips. (I however spent the better part of a day doing this, as I had never done an "under the
intake" starter before.) Seriously, I think a discount mechanic would charge you $500 to do this job, and some name brand outfits would charge a lot more.
The car now has about 87K miles, and the alternator went out a few thousand miles ago, so I figured I would replace the starter before it too failed. I have never had a problem with the starter, but with 8 years and 87K miles, I figure I would replace it at my convenience. Maybe I'm wasting my money, but if I got stuck somewhere on the road needing a new starter on this thing, I would be out a lot of money, plus a night in a hotel somewhere. Better safe than sorry, I reason.
Rock Auto prices continue to amaze me. I picked up the brand new (not rebuilt) starter for less than what most places were charging for a rebuild. And the Professional brand AC Delco parts don't require a core deposit/refund, making my life easier.
I also had no reason to believe the knock sensor was bad, but since it is below the manifold, cost less than $12, and only takes a couple extra minutes to replace once you're in there, I went ahead and replaced it too. (I like to run on regular gas, so correct operation of this sensor is critical to me, to keep the engine from knocking.)
It wasn't as bad of a job as I thought. You remove a couple crankcase vent hoses first, and one on the side of the
intake manifold. Push the connector latch to the side, and it pulls right off. Be careful of the cheap PVC black pipes! They crack very easy. Last year I cracked one, but it was easy enough to replace with a rubber hose. I think GM is trying to save every possible ounce of engine weight, or they would use a better material.
There is a long pipe that runs from the top of the water pump, along side the manifold, to the coolant overflow tank that has to be removed. This is the tube which is part of the self purging system, which gets air out of the coolant. I disconnected it from the side of the overflow tank. It will leak coolant after it is disconnected, so clamp it off or just raise the open end high enough so it doesn't leak.
Then the fuel injectors have to come off. You need a fuel line disconnect tool to do this, but it is only one connection. I disconnected the negative terminal of the battery first, so the fuel pump doesn't try to activate after pressure is released from the schrader valve on the fuel rail. The cheap plastic disconnect tool worked well. Just slide it up there inside the connection,and the fuel line pulls right off. (There is a clamp that hold the hole thing into place, for safety measures, but it snaps right off.) I have heard of others who had problems with the plastic disconnect tools, but I had none. Perhaps the metal one is a better investment if you do a lot of this kind of work.
Next you pull the wires off each fuel injector. Pull the connector tab up, then grab the locking tab with pliers from both sides, and the whole connector pulls right up off the associated fuel injector. The one on the driver side closest to the engine compartment is a bit cramped to remove, but not such a big deal.
Next, pull the fuel rail up with the fuel injectors still connected to the fuel rail. This took a little leverage and made me nervous, but those stainless fuel rails are pretty tough.
Now you can remove the
intake manifold. It's just ten bolts. I was shocked to lean that a couple of them were NOT torqued down at all, but were rather lose. I'm betting that some air was getting in there, but not much. I have no reason to believe this
intake manifold was ever removed before, but who knows?
Wedging the whole
intake manifold out of there is tricky, because there is little clearance between the manifold and the throttle body. (Both are attached by a rubber hose with a clamp on either side.) Eventually getting it back into place was also a pain in the butt, clearly the hardest part of this whole job.
After I got the
intake out of there the 8
intake gaskets looked just fine. They were dirty and coated with varnish, but were still pliable and rubbery. I probably could have gotten away with not replacing those.
Before I forget: I strongly suggest you blast all the dirt out of the top of the engine with compressed air BEFORE you remove the
intake. Once you get the
intake off all of the
intake valves are openly exposed, and any dirt left on the top of the engine can easily get down in there as you are trying to wiggle out the
intake maniforld. Immediately after you lift the
intake off, stuff a paper towel down each
intake hold to prevent more junk from going down there, and of course take them out before eventually reinstalling the manifold.
Once you got it all open, replacing the starter is easy. It's just held in by two bolts that are easy enough to remove. Plus, there are two electrical connections that need to be very secure.
Replacing the knock sensor is easy, just one bolt and the associated connector.
While you have the
intake manifold off, you get a direct view of the inside of the throttle body. After 87k miles, mine was filthy, as was the inside of the manifold. Left over reside from constantly recycling the gasses inside the valve covers, I would imagine. I used several cans of
intake cleaner for both. There is even a plastic drain plug that you can remove from the plastic
intake manifold to get the rest of the cleaning fluid out of there. I believe that cleaning the throttle body was a good idea, because that controls the idle. Had to do it again though, I'm not sure it was worth the extra time to clean out the inside of the
intake manifold. Even though there is a thick layer of gunk in there, it certainly is not enough to make a meaningful impact on the air flow, at least in my opinion. Unless some of that stuff eventually accumulates to the point where it breaks off and get sucked into the engine cylinder? All opinions welcome on this. It certainly can't hurt to clean it up with a few cans of throttle body
intake cleaner, I just question the usefulness of spending extra time cleaning up anything besides the throttle body.
Putting the whole thing back together was pretty straight forward. The one thing I forgot to do is to apply engine oil to the new o-rings on the bottom of the fuel injectors. I feel sorry for the next mechanic who has to pull out those fuel injectors, but I don't know if it is worth going back in there to coat them with oil. (I could probably get that far in less than an hour, now that I have recently done this job.)
You will need a torque wrench and the proper tightening pattern to reinstall the
intake manifold. I got that from alldatadiy.com
I will never know how much life that old starter had left in it, but I did notice a significant amount of electrical dust had already blown out the back vent of the starter, and had started to accumulate on the engine block. Clearly the original starter was worn, but who knows how much?
It didn't take long to start the car with the new starter, but of course you have to allow time for the fuel rails to repressurize, and purge themselves of air. After a couple minutes of running the engine stalled, and it took a few extra seconds (like maybe 30) to get it restarted. After that, no problem. It's interesting to note that on these modern cars you only tell the car to start by turning the key, and the computer takes over after that. For example, when there was still air in the fuel rails, the starter was still cranking even after I had released the ignition key. These cars are petty smart, and I assume that automatic starting function helps extend the life of the starter by not allowing you to crank while the flywheel is already moving. You can cuss all you want at the way the engineers crammed that starter under the
intake, but starters last longer than ever, and most of these Northstars will probably never have the starter replaced more than once, if ever.
