| How many miles has it got Sammy? I guess it has high milage? if so its extremely unlikely to be a Nikasil problem. From what I've heard these normally show before 50ish k miles and if they havn't by then then its very unlikely to become a problem later on. I'm no mechanic but the fact that its ok when cool and has problems when hot will point to specific things to check. The lack of thermostat is not a problem, people often remove them if it has gone and they can't get a replacement for whatever reason. They just help the engine warm up quicker by stopping the coolant flow from cold. I'll ask crazydave what he thinks if you want as he's an engine guru. |