Quick history:

Bought this 99 Blazer 3 weeks ago and had to add coolant on day 2 about 1/2 gallon. Previous owner is a friend and thought the heater core might be the culprit. Yes I do have the sweet smell through the vents and the passeger side floormat is a bit damp so I do think the heater core is leaking.

However, I started to get lifter knock like everyone else knows about here but goes away after warm up. I decided to change the oil even though it only had 1,000 miles since previous owner had dealer change it. That oil was in the engine from July 2009-March 28, 2011 with only 1,000 driven as he rarely drove this vehicle, only 1,000 miles on the oil in 18 months.

I changed the oil and filter and sent the oil into Blackstone for analysis.

I suspected my lower intake manifold leaking because of coolant loss and a small plate sized slippery residue puddle under the engine on the ground.

Strange, since I changed the oil the lifter knock is gone (suspect I got some crud out cuz the filter drain plug was caked with black sludge). The small puddle under the truck that appeared to be coolant before is now gone though. However, I know better and figured it was leaking internally into the oil.

Here are my results from Blackstone I got back today as compared to what they say are universal averages: Listing only the ones that are way out of wack in parts per million. My engine figures first followed by averages.

Iron 34 14
Copper 28 8
Lead 81 8
Tin 10 1
Potassium 61 2
Sodium 1055 13

Antifreeze % 2.11 should be 0

So there you have it. Copper Tin and Lead are not good on the bearings and the crankshaft does not like Iron. Time to tear it down.

Question...what would you guys do first the heater core and flush system and replace with green (will have shop do that) or do the intake first then deal with the heater core. Either way I'm going green coolant and will get flushed 2 times because of these 2 problems.

Thx

 

Do a cooling system pressure test to confirm or deny a loss of pressure. If it indicates a leak, diagnose it. If the intake gaskets are leaking, replace them first. OEM gaskets are a known common issue. Felpro MS98002T is an improved design gasket and will not leak if installed correctly. Do not use ethylene glycol, (green coolant) use Dexcool only. Even if you flush the cooling system completely, and then install the green stuff, you'll continue to have cooling system problems. Any shop that tells you differently is after your wallet, don't do it. You can read more here: http://www.ricksfreeautorepairadvice...-wrong-coolant