1998 plymouth neon problems neeed advice asap!
whichwitch00
05-26-2007, 11:13 AM
the other night my nephew was using my car - it stalled out and water was leaking from it i had it towed to my mechanic the water pump cracked and knocked the timing belt off line he placed both and car still wont start he is talking about bend valves ? the car never ran hot my nephew said . does this sound right ? is it an expensive thing to replace ? do they just replace vales and seals or do i need a new motor which i hope not my total bill at mechanic is already 265 its memorial day weekend i have no car and my birthday is on the 31st this totally sucks any advice would be appreciated . i also kno wi need a new catilyst converter which i am having my mechanic put on .:banghead:
denisond3
05-26-2007, 06:11 PM
Im sorry to have to give bad news.
If the timing belt got knocked off while the engine was running, the likelihood is that you have some bent valves - since any valve the camshaft is holding open will be smacked by a piston coming to the top of its stroke. With the timing belt keeping the camshaft and crankshaft in sync this wont happen. With the belt giving way its likely valves were bent, unless the engine was turning very slowly - like at an idle.
If the mechanic has replaced the timing belt already, a compression check should be done on the engine. If the compression is good - then you dont have a valve problem, and you would have to look elsewhere for the refusal-to-start. If the compression is 'low' in one or more cylinders, then you have one or more bent valves. The (only) fix for this is to remove the engine head and replace the bent valves. While the head is off the car you basically do a valve job on the engine head and replace the camshaft seal and the head gasket. This will be a few hundred dollars. I would expect the valve job on the head would cost at least $250, plus the labor to remove/replace it would be a similar amount. Thats if you live in a low cost area. I presume the water pump was already replaced? If it wasnt yet it certainly should be, and along with the new timing belt, a new idler pulley should be have installed.
But then you would have a good running car that would be ready for the next many tens of thousands of miles.
The timing belts on Neons are supposedly expected to last 100,000 miles. I replaced the belt on ours, and replaced the water pump (and the timing belt idler pulley) at the same time - since both jobs involve much of the same procedures for access to the parts.
If the timing belt got knocked off while the engine was running, the likelihood is that you have some bent valves - since any valve the camshaft is holding open will be smacked by a piston coming to the top of its stroke. With the timing belt keeping the camshaft and crankshaft in sync this wont happen. With the belt giving way its likely valves were bent, unless the engine was turning very slowly - like at an idle.
If the mechanic has replaced the timing belt already, a compression check should be done on the engine. If the compression is good - then you dont have a valve problem, and you would have to look elsewhere for the refusal-to-start. If the compression is 'low' in one or more cylinders, then you have one or more bent valves. The (only) fix for this is to remove the engine head and replace the bent valves. While the head is off the car you basically do a valve job on the engine head and replace the camshaft seal and the head gasket. This will be a few hundred dollars. I would expect the valve job on the head would cost at least $250, plus the labor to remove/replace it would be a similar amount. Thats if you live in a low cost area. I presume the water pump was already replaced? If it wasnt yet it certainly should be, and along with the new timing belt, a new idler pulley should be have installed.
But then you would have a good running car that would be ready for the next many tens of thousands of miles.
The timing belts on Neons are supposedly expected to last 100,000 miles. I replaced the belt on ours, and replaced the water pump (and the timing belt idler pulley) at the same time - since both jobs involve much of the same procedures for access to the parts.
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