My previous car was totalled and while shopping for used cars, I have found a 2005 Nissan Sentra 1.8S on sale for a very good price. It is being sold by the current owner, and it has been going to the Nissan dealership pretty regularly for routine maintenance (oil, filter change, eetc), so I am happy with the current state of the car.
It has clocked ~50k miles and that, I guess puts it in the "major preventative maintenance" mode.
The owner had never "popped the hood" before, so, when I did, to check the engine out, I noticed the following:
The Engine coolant reservoir has an absurdly low level. It's like 5% of the reservoir volume.
I am sure that, any vendor, including Nissan does a check of the coolant level during their routine maintenance, and the last check was 9 months ago, and given that the car had been driven around only 10k miles since, I am concerned about coolant leakage.
I asked the owner to turn the engine on and the exhaust does not blow white or blue smoke, so I guess that rules out coolant leaking into the engine?
The engine made a screeching noise for the first 5 - 10 minutes after a cold start, like this: http://www.youtube.com/watch?v=abqYkjT2zf4.
I could not see the belt drive closely enough but the "serpentine" belt drive design itself looks a bit weird: there's the belt coupled to a basic pulley system on both ends and the whole setup is under tension somehow and that worries me:
i. I am unable to closely inspect the state of the current belt and can't confirm if the noise is due to the belt itslef or from the power steering belt!
ii. If I end up buying this car, I would have to go through a lot of trouble loosening the tension and putting it back on just to inspect the state of the current belt, and I am not aware of any other system on the car that can make such a screeching noise (need help and suggestions here)
This model has large number of reports of a blown head gasket. http://www.carcomplaints.com/Nissan/Sentra/2005/engine/blown_head_gasket.shtml
My assumption is that these reports are an insignificant portion of the total amount of models sold in the US (otherwise they would have been legally required to do a recall, wouldn't they?).
If my assumption is false, then Nissan is an irresponsible company indeed, and I should not buy this car (or any of their models) to begin with, but given the large number of Nissan Altimas I see around, I would like to believe that those reports of a blown head gasket is within a small margin.
Keeping that in mind, short of an expensive ($200+) pressure test, how can I confirm or estimate if this particular car could be one of those with a blown head gasket in the future? (The absurd coolant level worries me)
Or, failing that, is there any "preventative maintenance" I could do to keep the gasket from leaking?