I have a 2008 Dodge Grand Caravan SLT 4.0ltr V-6 with a blown head gasket that local mechanics are refusing to repair, because the car has over 150,00 miles on it (184,000) Apparently, the concern is the health of the lower end of the motor. But if the oil is clean the head gasket replacement shouldn’t be a problem, correct? I can’t afford a newer car or a new motor for this one…as it is, the gasket replacement is going to set me back and I really need the transportation. What do I do?
In your case, I’d add sodium silicate to coolant.
I keep a bottle of it in the shop for situations such as this.
Automotive repair
Sodium silicate is also used currently as an exhaust system joint and crack sealer for repairing mufflers, resonators, tailpipes, and other exhaust components, with and without fiberglass reinforcing tapes. In this application, the sodium silicate (60–70%) is typically mixed with kaolin (40-30%), an aluminium silicate mineral, to make the sodium silicate “glued” joint opaque. The sodium silicate, however, is the high-temperature adhesive; the kaolin serves simply as a compatible high-temperature coloring agent. Some of these repair compounds also contain glass fibres to enhance their gap-filling abilities and reduce brittleness.
Sodium silicate can be used to fill gaps within the head gasket. Commonly used on aluminum alloy cylinder heads, which are sensitive to thermally induced surface deflection. This can be caused by many things including head-bolt stretching, deficient coolant delivery, high cylinder head pressure, overheating, etc.
"Liquid glass" (sodium silicate) is added to the system through the radiator, and allowed to circulate. Sodium silicate is suspended in the coolant until it reaches the cylinder head. At 100–105°C (212-221°F), sodium silicate loses water molecules to form a glass seal with a remelt temperature above 810°C (1,490°F).
A sodium silicate repair can last two years or longer. The repair occurs rapidly, and symptoms disappear instantly. This repair works only when the sodium silicate reaches its “conversion” temperature at 100–105°C. Contamination of engine oil is a serious possibility in situations in which a coolant-to-oil leak is present. Sodium silicate (glass particulate) contamination of lubricants is detrimental to their function.
Tester
It’s not just the lower end of the engine. If this failure happened because overheating was involved that can affect the cylinder walls and piston rings. Once the head gasket is replaced you may be left with an engine that smokes and consumes oil at a high rate.
I always run both a dry and wet compression test on all cylinders before replacing a head gasket. That test will not be accurate on cylinders that have a head gasket breach. However, it will tell you something about the cylinders that have not been breached. If problems are shown on the non-breached cylinders then it’s time for another engine, scrap the car, or go the sodium silicate route.
A head gasket repair is $1500. Or more. You can shop around and I’m sure you can find a shop to do it. Shops like money.
And keep in mind that sodium silicate involves a breach into the water jacket. It won’t do much good on a breach between cylinders or into an oil galley.
Always the unknown details as “blown” could mean weepage or total catastrophe depending upon a number of things. And since it’s a V-6 this means both gaskets should be replaced even if only one has failed.
I can understand the mechanics reluctance to repair this and do not fault them for their refusal. Something like this can end up badly. Replace the head gaskets and the engine turns out to be a major oil burner or has a knocking noise guess who often gets the blame. Not saying that you would do this; only that it is not a rare thing to happen. If severe overheating was involved I would likely refuse to repair it also.There are some repairs that it’s best to avoid leaving fingerprints on.
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Thanks for the advice guys… I have taken the van to get a second opinion, and he actually tore the top of the motor off and looked into the number three (the code said 3 was the culprit) cylinder and it had lots of antifreeze/water in there! So, new (used) motor in my future. Found one with only 40,000 miles on it for only $1600.00. My new mechanic will do the whole job (motor, assorted parts, gaskets, and labor) for $2950. I’m thinking I’m getting a pretty good deal, considering the first mechanic quoted $5,000. for the motor alone!
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