intake manifold replaced - when to chg oil?

[terminaldegree]

Hi All,

I recently replaced one of those p.o.s. composite upper intake manifolds on a gm 3800 series II. It was leaking some coolant into the combustion chamber-- not enough to hydrolock the motor, but enough that I noticed the level was dropping in the expansion tank.

After finishing the job, I changed the oil and filter with some $.68 car and driver oil and a supertech filter [
How long of an OCI would you do in this particular situation? I have a stash of 10W-30 maxlife synthetic and some good quality filters waiting for this car with the intention of doing 5,000-7,000 mile oci's. I don't want to waste the money I've saved by needing to change them out often.

Thanks in advance for any advice.

 

[jason07-1zzfe]

500 mi max unless you put in some LC or ARX and follow thier procedures. I would be using one of them if it were mine. After flush I would go back to regular OCI.

 

[Elroy the Unique]

What did you replace the plastic manifold with? How many miles were on your car when the plastic one failed.... I have care with the 3800 Series II and this really worries me.

 

[terminaldegree]

We bought the car used with 69,000 miles. The replacement is plastic also, but claims to be "beefed up" around the egr stovepipe [the problem area]. Apparently, this is the one achilles' heel of this powerplant. I think all series II's [with possible exception of the last couple of years] are susceptible to this.

Watch your coolant level like a hawk. Look for external leakage around or below the throttle body. The replacement cost me $130 [plus a new set of plugs] at a parts store, and I replaced it myself. It took me a while to fix, but I'm notoriously slow and meticulous.

All other responses to the previous question welcome!

 

[Ugly3]

Run the oil 5,000 or 6,000 miles and see how it looks.

 

[Al]

I'd run a couple 2K oil intervals and do an oil analysis on the third.

 

[JHZR2]

change it now (if you analyze this oil itll look like you still have a leak... I know this from experience). then, change it in about 1000 mi, then go to a 3000mi, then your usual oci.

JMH

 

[AstroVic]

I had an intake manifold crack on my 2000 Ford Crown Victoria. I changed the oil and filter immediately after replacing the manifold. I used Chevron Delo 15W-40 for about 100 miles. I then changed the oil and filter again and used my regular 10W-30 for about another 500 miles. I then changed again just to be certain, and it's been regular oil changes ever since.

It didn't really cost much to change the oil a coupla extra times, and it gave me the peace of mind knowing I wasn't driving around with trace amounts of coolant grinding away in my block.