So I took my car to the mechanic recently and they found my MAF was bad and my EGR tube had holes in it. They repaired those items, however, I am still getting a code 15 for low coolant temperature, the radiator fan always runs no matter what, and ocassionally at idle or crusing the engine surges a couple hundred RPM. Recently I replaced the coolant temperature sensor as well thinking this might have something to do with part of my issues. Last night I replaced the EGR solenoid thinking that might be causing part of the problem with no success. One thing I did notice on the engine fan relay connector was the one pin looked like it got super hot at one point. I've replaced the relay and of course the fan works all the time. Does anyone have suggestions to correct the issue?

 

id like to know too, my cars been sat 2 month since last start, ran it for 2 hrs yesterday but fan always on, from start ? ( blimin lights wont go down either ! )

 

The mechanic working on mine said that I have a coolant leak at the intake manifold. They said I had low coolant in the radiator as well. Something sounds fishy because I still had a lot of coolant in the overflow tank. I would think the coolant would flow back into the radiator if it was low. Maybe if the cooling system has a leak the coolant would not get pulled back in. They also said the coolant might not have been getting to the temperature sender which I question as well. Anyways, I am having them fix the leak at the intake manifold which should be pricy. I figure while they are in there they mind as well take a look at the lifters and pushrods and replace those too on a motor with 234k miles. Not my kind of fun but I will update what happens.

 

First, in my own experience, most mechanics don't know jack about OBDI systems... They prefer OBDII, which basically tells them what's wrong, and OBDI leaves them scratching their heads.

Second, if you have coolant in the tank but it's not going into the engine, I'd look into either replacing the transfer hose or clearing it out, or possibly the radiator cap.

Third, code 15 with the fan running usually means that the coolant temp sensor is bad or not connected, and the ECM is seeing a temp of about -130*F. As such, the ECM has no idea what the coolant temp is, so it turns the fan on just in case the engine is overheating. While the sensor is out, get a funnel and stick it in the hole and fill the engine coolant that way to eliminate the air bubble that forms under the thermostat.

The intake is probably not leaking, but the intake to cylinder head gaskets may be. Or the heater core adaptor pipe at the front of the engine is, and that's an $8 fix anybody can do with just an adjustable wrench.

Last, just because the engine has 234K doesn't mean the pushrods (which are rarely bad except in the case of other valvetrain problems) and lifters are bad. If you're going to replace the lifters, you should replace the cam as well because new lifters plus old cam can mean lobe damage and you'd need a new cam anyways. As such, leave them alone.

Don't let someone who obviously doesn't know what he's doing rip you off.

 

I completely agree with you. I was skeptical to have them break down so much for what I thought was a more simple fix. However, I have been noticing leaking of coolant from around the intake manifold for a while. The mechanic told me while they were taking things apart they found a leaking injector. I replaced the injectors about 18k miles ago with Accel injectors. They also said they found some vacuum leaks. I won't know that I have been taken advantage of until I have a chance to look at what they are doing tomorrow. They wanted me to bring down the factory injectors I replaced so they could test them and possibly use them for replacement.

 

I had my mechanic tear down the intake and he found a leaking injector and two vacuum leaks. In the process he also found a problem with the threads in the intake manifold for the thermostat housing. I had a bolt break in this back in 2003 and the mechanic then used heli-coil to fix the threads. The current mechanic is not very confident in putting it back together without having it leak. I noticed there is a hole that will let coolant back up through the hole for the thermostat housing bolt. I do not think that is right and definitely could see how it could cause leaks. The problem is sourcing a 1988 2.8L V6 lower intake manifold. Does anyone have any suggestions how to fix this? If anyone has a lower intake manifold they want to sell me please let me know.

 

Check the classifieds here, b/c alot of guys have swapped those 2.8s out.

 

Thanks for the suggestion. I just checked it out and could not find anything. I started another post for parts needed. If there is a machine shop out there who can fix these manifolds it would be awesome.

 

Contact FLYNLOW92RS as he has a 3.1 he's parting out (same manifold with a plug in the back where your 7th injector is and another where the 7th injector switch goes next to the coolant temp sensor, pop them both and put everything back together).

:edit: Saw the pics... Whoever did that screwed it up bad. Shouldn't be anything RTV and/or a thermostat housing gasket can't fix if you can't get a new manifold (I wouldn't get a new manifold to fix that... RTV will hold just fine if you let it set up before refilling the coolant).

 

I thought some RTV would be fine too. I think the mechanic I have working on it just wants it to be perfect if possible. There is a parts place in Knoxville, TN that claims to have the manifold as well for $90. I should know more later this week what I am going to do. Thanks for the feedback Maverick, I appreciate it.

 

So I got a good intake from a fellow ThirdGen.org member. I had the mechanic install it and you would think everything would be ok right? Well apparently the mechanic who had been working on my car was transferred to another shop in the chain I went to. So another guy worked on it and hacked up my vacuum lines. They had leaks but the way he connected them is jacked up. My brake booster is connected to the outlet on the lower intake manifold. The vacuum lines from the throttle body are going to the connection on the top intake manifold. Then I have one vacuum line that is completely cut and not connected to anything. Worse yet apparently the RedTop battery of mine had a corroded negative side post terminal. What did they do? They hacked up my battery cable and made it into a top post cable instead of getting another battery. Needless to say I am pretty damn frustrated. The labels on the hood tell anyone who can read the routing for the vacuum lines. Instead of fixing it myself I am waiting for the manager of this store to take care of it. Why does it have to be so hard to find a good mechanic? Oh and I forgot they also said I needed a new computer. It's possible but heck with all the vacuum lines routed backwards I am beginning to wonder. To be continued...