Hello Everyone,

So lately I have been having a hell of a lot of problems with my blazer. It started with a coolant leak which was thankfully the intake gasket instead of the head gasket. To get this job done I brought it to a local mechanic and they took car of it. Ran good for about a week and then I started to get random misfires above 40 mph and also my RPM gauge jumps around on accelerations that bring the engine up past 3000 RPM. Also got a MIL light on with a P0335 code, Crankshaft Postion sensor Circuit. Brought it back to the dealer and got that fixed. They ended up replacing the ckp sensor. Car worked fine for a few days (six to be exact) and now misfires are happening again and the RPM gauge is freaking out again and the MIL is on again with the same code. Also, after driving above 55 mph for a while, when the vehicle is brought to below about 900 RPM the oil pressure drops and the check gauges light comes on. This probably has nothing to do with driving 55 but more with the engine being fully warmed up by the time I get of the highway.

So I just went through the service records from the dealer a little closer than I did before and noticed that they put 6 quarts of 5w20 in when I believe the recommend amount is 4.5 quarts of 5w30. I'm not so worried about the weights of the oil because they used a full synthetic (at least claimed to) even though I would prefer a 5w30 since I do a lot of highway driving. I was wondering if I can pin my problems on them putting too much oil in. I think I can for the oil pressure if it clogged up the pump or the filter but I am not sure about the misfires I am having. I never noticed misfires until I had the original service with this dealer. They started 2 weeks later.The first week that it came back from the original service I did not drive much. The second week is when I started my new job which requires quite a bit of traveling so I don't know if that is relevant.

So if anyone can tell me if too much oil is causing this that would be great. Regardless I'm going down there tomorrow to get a free oil change with the proper amount this time. Also my blazer has 143,000 miles on it.

Thanks for any help

 

6 qts? r ya sure thats not just a sloppy written 5? i`m glad i do my own repairs, i don`t trust shops anymore..

 

It was computer generated and its definitely a 6 unfortunetly. I normally do the repairs I can but didn't have time due to my new job and need my car to get there so was looking for the quick turn around of the dealer. Dont actually know if they are the ones that caused these problems but I am hoping someone can help me out here.

 

How bad was the coolant leak? Was the coolant getting into the crankcase? It might have caused some damage to the lower end bearings it had.

The shop putting in the wrong weight of oil is more significant than over filling it. Over filling it wont cause the filter or pump to plug up. possible frothing from windage and loss of economy might occur. The lighter weight oil is causing the drop in oil pressure at low RPM when the motor is hot. This will drop in pressure will be agravated if there is any bearing damage from the coolant leak.

Since they did the intake gasket, they had to pull the distributor. they may have routed the plug wires where one may be shorting to ground if its rubbing.

Good luck!

 

So I went back to the dealer and explained to them everything that they did wrong and what was wrong. I also showed them this thread. The ckp wasn't seated correctly and since it is basically a Hall effect sensor being a little out of position was a big deal. They changed my oil with the correct weight and amount. This fixed my oil pressure problem as kristoph30 suggested. They also admitted that it was their fault and didn't charge me anything.

Thanks guys for the help

 

Glad to hear they made it right!