Removed intake, found crystallized dexcool?
 

Hey folks, cruising right along with changing some leaking intake manifold gaskets and found what looks to be crystallized dexcool in the rear two passages. The right side looks completely blocked, the left side only partially. This is a 98 with 83,000 miles, runs great, gauges never showed anything strange. I haven't owned the vehicle very long, but I can tell you it looks like the radiator and possibly the heater core have been replaced prior to me. The coolant looked decent when I bought it, but I flushed the system anyway prior to discovering the leaking intake gaskets. I haven't touched the blockage to see how hard the deposits are yet.

So....what the heck is this, how did it get there, and how do I get rid of it?

Thanks everyone !!

Sorry guys
 

Sorry guys, search for the thread "another lim gasket job..." ( I couldn't figure out how to post the thread:) ). I even read that one not all that long ago:icon_screwy:

Looks like they did a great job at changing the oil regularly! Not so much with the cooling system. Dexcool needs to be flushed every 3 years or 36K miles. The rear passages do not go through the intake manifold. They dead end at the intake, and as a result the coolant doesn't circulate and it tends to sludge up if not maintained properly. The intake gaskets in the image are the OEM style and even the replacements will leak. Felpro MS98002T will not leak if clean up & prep work is done right. Make sure you chase the threads on the intake bolts, and in the heads, with a tap & die, then apply thread sealer. No need to replace the bolts. Sequence and torque is extremely important on this engine.


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That is the plan, thank you sir!

Captain do you know the thread size of the intake bolts?

Not 100% certain, but if memory serves correct, they are 5/16" X 18. Best to use a thread pitch gauge to be sure ;)

Ok. Thank you I will do that. Thanks again.


01 Blazer

Whooo hoooo, finally got around to starting it back up after completing the intake gasket swap ( AND... spider assembly upgrade, replaced oil pressure sending unit, cap, rotor, plugs, coil, some vacuum lines, big three with 1/0 wire, 200 amp alternator, 99+ steering wheel with audio controls, multifunction switch, all new moog front suspension components and hubs, calipers, pads, rotors, brake hoses, heater & radiator hoses, thermostat, radiator cap, and exterior bulbs all around...).

No codes and it runs great. Off to the shop for an alignment now. Thank you guys for all the great and helpful information!

Nice job! Make sure you ask the alignment shop to check & adjust the front chassis ride height while it's on the rack, and BEFORE they do the alignment. Let me know if you need specs and directions. You can actually adjust chassis ride height yourself if you choose.... not difficult at all.

Captain, you are referring to the "Z" height correct? Where did that name even come from? I left out the new torsion bars and PCV valve from my list of changes in the above post... Yes, I have spent that much on a silly 1998 Blazer;). I figure with only 83,xxx miles, it should be a decent vehicle for the children to drive in a couple years. Anyway... Yes, I plan to set the z height at 4.8 inches prior to taking it in for the alignment. Measure the difference between the center of the lower control arm bolt and the bottom of the steering knuckle to arrive at the z height correct? I know you have posted a very good image explaining it on a couple other threads. Much better than the picture of the angle given in the service manual from GM. I do have a question though. Is it common for the left and right adjustment bolts in the torsion bar keys to vary by quite a bit? When I removed the old bars, the left bolt was almost bottomed out and the right bolt was only halfway in. I didn't think to measure the z height prior to removing the old bars, just marked the threads with nail polish for re installation. Currently I just have both set at the halfway point for an initial measurement... Thanks!