66 Fastback":qflh8jwp said:
It sounds to me like he definately needed to replace the radiator and it is part of the core problem. Granted, there may still be other problems, but if there is no coolant flow through the radiator, it will heat up quickly and was not replaced to no avail. Now he needs to verify that the engine block has the ability to flow coolant.
Doug
See, this is the crux of the problem. The type of thinking illustrated here is what leads to the "parts replacement" process of troubleshooting, which is unecissarily expensive as well as time consuming and potentially embarassing.
A radiator shop claimed that his radiator was significantly clogged. That in of itself is not worth much. It is in their interest to sell you a new radiator.
But regardless, that has little to do with the issue at hand.
If the car truely overheats in 5 minutes, then the radiator has nothing to do with it. It may ALSO be clogged, which may lead to OTHER overheating problems - but that has nothing to do with the problem at hand. His replacement of the radiator to no avail proved this.
In order to successfully trouble shoot a problem, a person has to be able to focus on the problem. If your car was stalling at stoplights and you discovered that your wheel bearings were worn, would you replace them in an effort to fix the stalling? Of course not. They may ALSO be a seperate problem - but that is beyond the scope of the problem at hand. In this case it may not be so obvious that the problems are not related - and thats what the help of this forum is for.
The radiator, plugged or otherwise, is beyond the scope of his described problem. I as well as others agree(d) on this. It's been proven now - let's move on.
Being able to correctly seperate systems and understand their relationships (or lack therof) is crucial to troubleshooting something as complicated as a car. That's why this forum (and others like it) is so great... between the cumulative knowledge here, there is little left unknown. If you can't do this - you are lost staring at a device constructed of many interconnected parts - and when "something" isnt working right, all you can do is start replacing stuff.
That's how most mechanics operate - except they replace stuff on your dime. Car's overheating? Replace the radiator - no change? water pump... still bad? Oh... blockage in the block caused by corrsion... problem finally fixed.
What does the Mech tell you? "Yeah, you had a bad radiator, water pump, and some blockage in the block. Now please bend over." When you are paying for someones labor, it is sometimes even cheaper to go this way. It can get pretty expensive paying a mechanic hourly to think about your problem too much. Might as well have him replacing parts (good or bad) which are relatively low cost compared to his labor rate. If he stumbles upon a solution before he thinks it through, you win.
While taking this same approach is less expensive than letting the mechanic do it... most of us prefer to make informed decisions about what parts are likely at fault.
So, getting back to the problem at hand. If the engine is TRUELY overheating in 5 minutes (And I don't mean warm on the gauge, or 15 minutes) then the radiator, water pump, etc aren't likely to have anything to do with it. It takes longer than 5 minutes at idle for your engine to even warm up enough to open the thermostat. If you capped off the bottom water inlet, took the belt off the WP, and filled the block up from the top w/ water, it would run longer than 5 minutes before it started to boil.
Water takes a LOT of energy to heat, and there's quite a bit of it contained in the engine block.
So. What is more likely the case is that either a.) you are experiencing some sort of anomalous engine behavior that is dumping more heat than normal into the coolant (crack in block, headgasket to coolant passage, etc) or b.) you have some significant blockage in the block that is preventing coolant from going everwhere it is supposed to go.
There is also c. ) you are not filling the block sufficiently with coolant due to trapped air (see blockage) or d.) it's not actually overheating and you have faulty instrumentation (gauge, etc).
Generally, one would take the approach that yeilds the most information about these possibilities in return for the least amount of work/cost.
At this point for you, that would be a compression test. Good compression means that you probably don't need to worry about a. and can focus on b,c, and d. When I am dealing with these things, I personally like to rule in or out the most extreme situations so I at least know what my worst case scenarios are, and can plan accordingly (good compression, you know your motor's not trash)
And yes, there are exceptions to EVERYTHING. But a successful troubleshooter doesn't consider exceptions until all reasonable explinations have been exhausted. All too often (and this is what probably gets me going the most on here) people get fascinated by the possibility of an exception before they have investigated all reasonable options. 99.9% of the time, that results in a big waste of time and money.
This is one of the most common failures in my profession. I see engineers all the time who find a potential solution to a problem so sexy and mentally stimulating that they become blinded to the obvious explinations right in front of their face. Its only after expending large amounts of time and the companies money proving to themselves that they were mistaken do they come back around and realize the solution was simple all along. (computer doesnt boot? before you dissect the power supply looking for unanticipated eddy currents, try plugging it in!) KISS.
Disclaimer:
Myself, or anyone else who trys to help out w/ these things via the internet, is only as as good as the information given us. There is a big disconnect between sitting here at my desk reading a post, and in the guy's driveway looking at his car. It is the responsibility of the poster to be as accurate and complete with their information as possible in order to narrow this gap. If instead of 5 minutes it's actually 10 - or instead of overheat's it's actually "gets uncomfortably warm" then everything I or anything else said in response to this is totally worthless. Just like everything else in life, garbage in = garbage out.
Try a marine supply store,they should have some in stock.If not,they can order you one.
