Dodge Repair: 2000 Grand Caravan makes noises and shakes after running through water, grand caravan, warranty period

Question
Dear Sir:

Since I bought it within the warranty period, the mechanic for the dealer checked it for me. It took him around 10 days to figure out what you found. He took the engine apart and kind of thought the connecting rod is bent and suggested to change the whole engine. I just wonder if I can just change the connecting rod only or I have to change the whole engine. How much will it cost for each? Another possibility is that nothing is wrong, just there is water still in the engine, how can I check it out if there is really the problem of the connecting rod and not just the water?

Thank you very much for your help!
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Followup To

Question -
Dear Sir:

I bought this 2000 grand caravan recently. It drives fine but two weeks ago, I drove it down from a slope into water of around 20 inches high. After I went out of the water, the engine stopped working and I could not restart the car immediately. I tried several times later but it did not work. Around 15 minutes later, I tried to start it with my feet pushing the accelerator and it started but it made a tremendous noise. Later on the noise became weaker but it is still apparent and the car is also shaking when it is idle. At high speed, the noise seemed to be weaker than at low speed. The noise seems to be rhythmatic and its frequency is proportional to the speed of the car. The car also shakes at idle but did not shake at high speed.
Could you please give me some suggestions on what the problem might be and how much does it cost to repair it?

thank you very much for your help!


Answer -
Wow, drive me head first into 20 inches of water and see how I react !..............seriously though, you have picked up water into your engine through the intake / air cleaner system on your car; that is why it stopped working. Without seeing it or hearing it, I will give you two things that you MUST do..........

1-Change the engine oil and filter (even the slightest amount of water contamination here can be devastating to your lower end bearings and your cam bearings.

2-Have a compression test run on the engine; this will tell you where and how much damage is done to the engine mechanically; If you do not know how to do this, take it to a mechanic that you trust or go to an auto parts store and purchase a Chiltons repair manual for this model; it will show you step by step everything you need to know, in order to perform this test.

3-If, and that is a mighty big IF, your engine checks out mechanically, you may have only trashed the spark plugs.  Boy, that would be a nice save, wouldn't it?

Answer
Well.................first question, unless he took the engine apart, what method did he use to determine a bent connecting rod ???  The only true way is to measure ACTUAL top dead center on each cylinder with a dial indicator that will measure dimension differences in thousandths of an inch; Set up the dial indicator on each cylinder and rotate the engine over by hand until you reach top dead center ( in other words, when you see the needle on the indicator start to reverse rotation )

Okay, let's assume that he is right; the easiest, but also the most expensive way is to replace the engine with a rebuilt unit. If you are capable of a warrenty situation, I would go for it; even if you had to pay part of the cost, you would still have a new engine in a 2000 vehicle.

If you cannot go the warrenty route, and want to replace the connecting rod; then also replace the rod right next to it on the journal (rods not only will bend vertically but will also suffer "twist" across the grain of the rod.)  And last but not least, if you have it apart anyway, change the bearings front to back.  It is a lot easier and more cost effective to do it now.  also be sure to flush and clean the oil pump and refill it with fresh oil before using it.

Good luck..........if the engine is not too badly damaged or has excessive miles, you can probably get away with just replacing rods and bearings.  

Keep in mind though, if a shop is doing it, they will recommend that you not do it this way, for fear of it coming back on them at a later date.