Join Date: Aug 2011
Feedback Score: 0 reviews
The rule of thumb that I use is to assume the worst when it comes to purchasing a car with an overheating issue. What is the worst? Blown head gasket and warped cylinder head, water pump. Why I do that? Because very few sellers know the extend of the damage, and the ones who do may not disclose it to the buyer. You purchased a car with an overheating issue. Did all the right things (thermostat, sensor, wiring) yet the problem persists. I am starting to lean toward my worst fears. However, before I recommend taking cylinder head off, I would also recommend the following:
1. Identify the source of the leak. Based on the description you provided, I suspect that the coolant hose that connects to the intake manifold could be leaking at intake manifold gasket. Before replacing the gasket, I would first try tightening the nuts on the manifold, all around, but more so the ones that are in close proximity to the hose. Pressure wash the engine. Let it dry. Then check if the coolant keeps leaking from that area. If it doesn't, I would look around to see if there may be another leak somewhere. Now that the engine is clean it will be easier to identify the leaks. You could also use a die that will make the job easier. No leaks? Still overheats? Proceed to the next step.
2. Bleed the coolant system using 50/50 antifreeze/water mix
3. Confirm that the radiator fan is working properly
Still overheats? You likely have bigger issues. Back to my opening statement. Consider replacing water pump first. I suggest replacing the timing belt and t-belt tensioner at the same time. Unless you have a proof (pictures, receipts from the previous owner) that these have been replaced. However, even if the water pump was replaced, unless you have a receipt you don't know where the replacement pump came from. May be it wasn't all that good of a quality to begin with.
Pump replaced, system bled, still overheats? For me it would be time to remove cylinder head. Once removed, use a straight edge to verify that it isn't warped (readings exceed recommended service limit for cylinder head warpage). If it isn't warped, verify that the deck on the block isn't damaged (deep scratches, dings, corrosion etc.). Same for the head mating surface. Unsure whether or not the found imperfections are acceptable or not? Just take close up, good quality pictures and post here for review. If the head is warped, you can shop around for another head or have yours machined. When purchasing new head gasket, go with OEM quality. More money? Yes, but you won't have to do this over again. You don't want to gamble with a head gasket. I made that mistake before by purchasing Ebay quality $19 head gasket for my Integra back in the days.