Concern For 1988 Reatta Engine

[Voltaic]

It seems like one thing after another with this engine. I recently replaced the cam magnet proper, as well as the timing set shortly after since I was now confident in how to quickly and properly replace everything in that area. It felt great to have power and mileage back, but I didn't have that for long. At some point in the past two weeks, I developed some sort of my nternal oil leak, as I'd gone through two quarts in that time period, and my mileage and power tanked once again. I pulled plugs to see if it was valve covers, they were clean, checked my lines and they were secure. Fluids weren't contaminated, so I was beginning to worry about the bottom end.

 

I don't really have the cash or time at the moment to break down the engine, as it's currently my daily, so I opted to go for a crankcase stop leak... and it worked, spectacularly even. Mileage back in the twenties and power restored. What do the minds here on the forum think of this? Mileage now at 145k(mostly highway at this point) did a tuneup after timing set replacement, haven't done a compression test yet, and I've been staying within 5 of speed limits.

[2seater]

Maybe I am not quite understanding the post above? Was it an internal or external oil leak? The word nternal could go either way. What plugs get pulled to check valve covers? The comment about going through two qts. would seem to indicate it leaked out unless you are indicating it somehow held two qts inside the valve covers or the valley. Did the engine get noisy, like lifters ticking? 

 

An external oil leak of that magnitude would seem obvious, which would be the only reason for stop leak? I cannot think of any reason that an oil additive would restore power and mileage unless it is simple coincidence or perhaps the lifters collapsed due to lack of oil which would tend to hurt power output. I am pretty familiar with the insides of these engines and am trying to imagine any adverse effects on the engine as a whole if only the front of the engine was opened up. Maybe too much silicone used which got into the pan and restricted oil pickup. Curious situation.

[Voltaic]

Whew lord, sorry about that mess of text, I wasn't watching how I was typing and was quite tired from work. I try to post after work and I never seem to get my point across.

 

It was internal as far as I can tell, there wasn't any sign of an external leak. No puddle underneath and no dripping down the side of the engine that I could see. Lifter tick was there from low oil, but left once I'd added things. I pulled all of the plugs to check and there wasn't oil on any of them, and no oil along the valve cover surfaces. I then checked both radiator fluid and oil to see if one had leaked to the other in case of a gasket leak, and both were solid colors, not milky or anything. I was tired, added the stop leak and more oil, and within I want to say 15 miles everything seemed to be righted. No more oil loss and performance restored. I'm more framiliar with the 3800 Series II, so I'm not quite sure were this oil may have gone to get burned off. I'd just like to have an idea when I do have the time in the future to sit down with this thing, a Haynes Manual, and a rebuild kit.

 

Edit: I can't quite recall the stop leak product specifics, but I'll be at the same store today to pick up some bobs and bits and will get that info here to help paint a better picture.

Edited November 12, 2021 by Voltaic (see edit history)

[EmTee]

Intake manifold vacuum leak?  Is the car leaking any coolant?

[Voltaic]

I apologize for dropping things, work kicked up and then the holiday happened.

 

The car is doing fine on fluids now, no burn on coolant or oil anymore, and again no contamination. I'd used Bar Seal's High Mileage Engine Repair. It seemed to clear things up within a day of using it. I'm wondering if the piston rings are starting to go. As far as I'm aware, the bottom end is entirely original. On a side note, I believe I've developed an exhaust leak on the crossover pipe, how much of a paint is that to deal with?

[2seater]

145k miles is relatively low and should be of no cause for concern unless it was abused in a past life? When the front of the engine was opened up it should have been a good time for a visual inspection inside the front of the oil pan and the area around the timing set. All should have been clean with limited areas of discoloration.

 

The crossover pipe is relatively easy to access. My memory is only so-so on what it looks like since mine is now very different. At the very least, remove the hose between to the engine and the air filter housing. The connection to the forward manifold is two studs and nuts. The small bracket attached to the front head and the pipe connection must be removed. Personally, I remove the bracket and do not reinstall it. It just makes alignment of the parts more difficult and supports nothing. There is no gasket used at the forward end of the crossover. It is a sort of ball and socket arrangement. The rear connection is secured by two long bolts under the heat shield for the throttle cables. The actual connection is made with the crossover pipe inserts inside a flared area on the rear manifold. The crossover pipe has a doughnut shaped graphite seal that is pressed into the flared connection with the rear manifold by a movable clamp ring on the crossover and the two bolts. After the fasteners are removed, lift the front connection up first and then pull the pipe out of the rear.

 

When reassembling tighten the fasteners alternately and slowly at each end. There is no stop or other indicator that they are tight, just a feel and then test for leaks. One other thing; if there is a substantial exhaust leak at the crossover, which is unusual, it can introduce ambient air into the exhaust upstream of the O2 sensor at the rear and interfere with a correct reading and fuel correction.

[Voltaic]

12 hours ago, 2seater said:

145k miles is relatively low and should be of no cause for concern unless it was abused in a past life? When the front of the engine was opened up it should have been a good time for a visual inspection inside the front of the oil pan and the area around the timing set. All should have been clean with limited areas of discoloration.

 

The crossover pipe is relatively easy to access. My memory is only so-so on what it looks like since mine is now very different. At the very least, remove the hose between to the engine and the air filter housing. The connection to the forward manifold is two studs and nuts. The small bracket attached to the front head and the pipe connection must be removed. Personally, I remove the bracket and do not reinstall it. It just makes alignment of the parts more difficult and supports nothing. There is no gasket used at the forward end of the crossover. It is a sort of ball and socket arrangement. The rear connection is secured by two long bolts under the heat shield for the throttle cables. The actual connection is made with the crossover pipe inserts inside a flared area on the rear manifold. The crossover pipe has a doughnut shaped graphite seal that is pressed into the flared connection with the rear manifold by a movable clamp ring on the crossover and the two bolts. After the fasteners are removed, lift the front connection up first and then pull the pipe out of the rear.

 

When reassembling tighten the fasteners alternately and slowly at each end. There is no stop or other indicator that they are tight, just a feel and then test for leaks. One other thing; if there is a substantial exhaust leak at the crossover, which is unusual, it can introduce ambient air into the exhaust upstream of the O2 sensor at the rear and interfere with a correct reading and fuel correction.

Gotcha, so maybe this may have been some weird incident. From what I do remember of all the components from old to new, the old damper quite literally fell apart once it had tension off the chain, and the timing set itself had heat scoring on the chain, so perhaps it had some heat issues in the past. The last owner had let their son use it to get to and from college, so I can only make inferences what happened during that time. Past that I do know it was a garage queen.

 

In reguards to the exhaust, I do have a moderately strong, rich exhaust smell in the bay and a wee bit in the cabin, along with an occasional pop around the crossover when pressing the throttle. I'll keep the advice/instructions in mind for a weekend afternoon.

Edited November 30, 2021 by Voltaic (see edit history)