- Mar 9, 2018
- 3
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Hey everyone! I'm having an issue (or maybe 2 separate issues) with my 98 that I can't seem to figure out. Sorry for the long post, but I'm going to try and explain this the best I can.The car has about 200,000 miles on it and it's stock. I've had slowly disappearing coolant for a while (no signs of a leak that I could tell) and it hasn't really worried me that much. I check the level frequently and keep it filled and I haven't had any overheating issues. I figured that the water pump was probably starting to weep, since it is the OEM pump. Within the last few weeks, it's gotten worse and I can smell coolant now when I get out of the car. I started looking around and can't find any coolant leaking from the pump. I did notice one drop of coolant around what I think is the lower intake manifold where it meets the block. It looks like there is a rubber gasket there that could potentially be leaking.
I'm not sure if this is related but the car also idles rough when restarting when the engine is hot. Today, I drove probably about 12 miles into town and stopped for gas. It restarted fine after that. I went maybe another 10 miles or so and went in a store for about 20 minutes. When I tried to restart the car, it idled very rough and knocked off. When this happens, I have to put it in gear and go as soon as possible to keep it from knocking off. Then it kind of sputters and stumbles while I drive out of the parking lot. The more short trips I make once it's up to temperature the worse it is. But, once I get moving, everything seems normal. It idles fine at stoplights and if I put the car in park and leave it running it's fine - the idle's not perfect but no where near bad enough to knock off.
I also have a check engine light. It had 2 codes P0171 and P0174. I did some research and someone suggested checking the fuel trims to see what was going on. The long term fuel trims are way off - like +25%. The short term fuel trims are within +- 5% at idle and go up to 20-25% when the engine is under load. I read somewhere that if the fuel trims are registering like this, it could be an EGR/DPFE sensor issue. I cleaned the MAF sensor and also replaced the DPFE sensor (which did test bad) and that didn't help. Another possibility was a fuel delivery issue, but I would think that would cause problems all the time if that were the issue. I thought maybe if the intake manifold gasket was leaking, it could cause a vacuum leak? But, don't vacuum leaks show high fuel trims at idle and normal fuel trims under load? I don't like to just throw new parts on, without having a reason, but I'm running out of ideas.
Does anyone have any suggestions of things to test? Could these 2 issues be related? And if the lower intake manifold gaskets need replacing, is that really bad news for the engine?
Thanks for any help,
Rebecca
I'm not sure if this is related but the car also idles rough when restarting when the engine is hot. Today, I drove probably about 12 miles into town and stopped for gas. It restarted fine after that. I went maybe another 10 miles or so and went in a store for about 20 minutes. When I tried to restart the car, it idled very rough and knocked off. When this happens, I have to put it in gear and go as soon as possible to keep it from knocking off. Then it kind of sputters and stumbles while I drive out of the parking lot. The more short trips I make once it's up to temperature the worse it is. But, once I get moving, everything seems normal. It idles fine at stoplights and if I put the car in park and leave it running it's fine - the idle's not perfect but no where near bad enough to knock off.
I also have a check engine light. It had 2 codes P0171 and P0174. I did some research and someone suggested checking the fuel trims to see what was going on. The long term fuel trims are way off - like +25%. The short term fuel trims are within +- 5% at idle and go up to 20-25% when the engine is under load. I read somewhere that if the fuel trims are registering like this, it could be an EGR/DPFE sensor issue. I cleaned the MAF sensor and also replaced the DPFE sensor (which did test bad) and that didn't help. Another possibility was a fuel delivery issue, but I would think that would cause problems all the time if that were the issue. I thought maybe if the intake manifold gasket was leaking, it could cause a vacuum leak? But, don't vacuum leaks show high fuel trims at idle and normal fuel trims under load? I don't like to just throw new parts on, without having a reason, but I'm running out of ideas.
Does anyone have any suggestions of things to test? Could these 2 issues be related? And if the lower intake manifold gaskets need replacing, is that really bad news for the engine?
Thanks for any help,
Rebecca