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Discussion Starter #1
Well, I'd been meaning to get around to starting a thread of sorts on the S4. This isn't exactly what I'd planned, but I guess it'll work. I kinda liked the "Hussy'' thread, and ironically, I'd called the S4 the old hag as soon as I brought her home. I'm a single dad, and I told my daughter that the bikes were gonna be jealous of the old hag I was parking in their garage... My two Buell street bikes being 03 and 04, the race bike being an 04, and my daughters bike being a 03, the 94 S4 became the oldest girl we had.

So, since I never got around to documenting that like I wanted to, I figured I'd go ahead and document the engine rebuild. Figured pictures here would help me remember where things go, and I'm sure I could use some input along the way.

So, here she sits as she came home last week. First time I'd had her on a trailer, as my daughter and I drove her back to Oklahoma from Florida.
 

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Discussion Starter #2
a friend of mine helped me pick her up and off load her in the garage. As I mentioned before, sounded a lot like a rod bearing spun, but I won't know till I get inside. In the mean time, I removed the hatch and started on it. Checked the normal, oil looks good.

It'd been changed 1100 miles ago. Mobil 1 V-twin synthetic 20W-50
 

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Randy or Tom one had asked me about the boost controller. I'll be honest, I'm not really familiar with how this all works. I've only owned turbo diesels before, and they've been mechanical waste gates. Well, the Civic I'd turboed, but it was a mechanical waste gate too...

So, here's what the boost controller looks like.
 

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Discussion Starter #4
so, anyone that can educate me, please do. I'd like to know/understand more of what's going on with all that mess of vacuum lines and electronics.

Moving on, as luck would have it, the Alunox header arrived Monday, after the engine was in it's state, and after me in mine.

So, here's the Lotus porn.
 

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Discussion Starter #5
on the plus side, I guess the engine need darn near half pulled to change the header anyways, so, guess this will help with that.

Since I'm going to be in there anyways, I'd planned a few upgrades. I'll take any information about upgraded/larger radiators anyone has tried. I really just want to stay with the Lotus Charge cooler. The Alonux is nice, but frankly I like seeing the Lotus one there. I will try to improve it's flow similar to what was done with Hussy.

Turbo will need gone thru since the bearings may or may not have metal in them, so, I thought a T3/T4 turbo would be in order. Seems like a good time to have a midpipe built to replace the cat while I'm at it. Found the 104* pulleys, they are actually pretty cheap. Race chip/programing... what's everyone done? Complaints one way or the other? The Buells you can actually tweak with a program called ECMspy and a cable. I can adjust all my maps, cooling fan temps, rev limits, etc etc. Entire system is adjustable.

Now, my current limitation, I just got out of the hospital from left shoulder replacement surgery.
 

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Discussion Starter #6
Oh, if someone with a S4s or a V8 could take some pictures of the wire routing for the mini tail gate mounted antenna, I'd like to see them. While I'm in there doing everything, I'm going to do away with that cheesey monstrous power antenna in the rear quarter panel. I'd like to go with the tailgate mounted antenna, and even then, I'll probably swap the whip with a small carbon piece.
 

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That's not a boost controller. What's in your pic is the vacuum pump and the two solenoids which are supposed to operate the throttle jack and the exhaust back pressure valve (EBPV). They have been eliminated from doing their jobs as evidenced by the blue hose that is linked to the inlet/outlet on each one.

This in itself is not a problem and is a common modification as their main functions have to do with emissions control. The ebpv is a valve located in the exhaust pipe between the catalytic converter and muffler and is typically closed at cold startup to reduce the amount of time it takes to warm up the cat to operating efficiency to reduce CO emissions. The throttle jack serves to raise the idle at this time to keep the engine from stalling due to the increased back pressure in the exhaust system. Those two solenoids control those functions.
Most owners remove or disable the ebpv and throttle jack which appears to be what has been done on your car.

There should be a third solenoid on the other side of that engine bay wall which does control turbo boost and is managed by the ECM. Take pictures of that and those lines so we can tell if it's hooked up properly. It should have two lines, one to the intake side of the turbo and another to the turbo wastegate actuator...
 

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Barry, just as Jim said, that is the vacuum pump and the 2 non functioning solenoids for the throttle jack and the EBPV valve which your car doesn't have. The vacuum pump on your car only runs the HVAC system.
The solenoid for the wastegate capsule is on the other side of the same wall.

The wastegate solenoid is controlled by the ECM and allows boost beyond the mechanical wastegate setting. It is my understanding that a failure of tje solenoid would not allow overboost to occur.

I don't think that has anything to do with what happened, and I doubt that you overboosted.
 

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Discussion Starter #9
Yea, I doubt I overboosted causing damage myself. I've spun rods before, and I'm pretty sure that's what happened. I know the oil temp got hot, and taking off from the light I lost oil pressure for a second. Light came on, and gauge dropped... then it shot up. I'm not able to do much to it at the moment though. I'm thinking the problem originated with the high oil temps, my question is what did I do to get the oil temp so high...
 

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Thinking about the oil temp shooting up I wonder if there could have been a blockage to the oil cooler or a problem with a hose going to the cooler?

Just a thought.

Robert
 

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Discussion Starter #12
I'd think a blockage to the coolers/cooler would cause a lose or increase in oil pressure, at the time, oil pressure was normal. I was however pushing the car pretty hard at the time, so elevated oil temps aren't a huge issue, but, I should be able to push the car pretty hard, it's a Lotus Esprit...
 

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Check your compartment with the ECU for the relay/fuses/inertia switch. That is the the P.O. put my wiring.
Trying to sort out what was eliminated in mine, as mine looks a bit like yours.

Would love to see the wiring/fuses/inertia switch set up when you locate everything. Best of luck, Josh
 

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Yea, I doubt I overboosted causing damage myself. I've spun rods before, and I'm pretty sure that's what happened. I know the oil temp got hot, and taking off from the light I lost oil pressure for a second. Light came on, and gauge dropped... then it shot up. I'm not able to do much to it at the moment though. I'm thinking the problem originated with the high oil temps, my question is what did I do to get the oil temp so high...
It sounds like you put at least 3000 miles on the car since you had it and we put several hundred on before that. I assume you had not noted low oil pressure before or high oil temps before.
You haven't mentioned any leaks so we should be able to assume an adequate oil level. That then would lead one to think of possible problems with the oil pickup or pumping, or obstruction. A low volume of oil being circulated would lead to high oil temps as well as inadequate lubrication.
The fact that oil pressure dropped and then shot up makes one wonder either of starvation or a faulty pump.
You will need to investigate the oiling system when you take the motor apart.

We certainly will give you all the support we can in figuring out what happend and getting it fixed. Good luck with the shoulder.

Randy

Randy
 

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I'm not sure how the oil pickup is in these engines, but you might have an issue with a loose pickup. If the pickup mounting bolts are loose, you could have fluctauting oil pressure.
 

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Discussion Starter #16
Randy, I've keep a good watch on oil pressure and temps. No issues. I've put over 4000 miles on it. Changed the oil right after we got home from Florida, then changed it again at 94000 miles. Oil level is fine, not lost any. No leaks. Clutch line did work loose and was leaking for a bit. It was at the slaved cylinder. Tightened and bleed it and it's been fine since. Oil level in the pics has about 1100 miles on it, and it's right in the middle, and looks clean still. No ''glitter'' on the dipstick, but that's a pretty small sample.

Frankly we're just kinda guessing at this point mostly, but I am gauging ideas and thoughts. No matter what, it's got to be pulled and gone through to find out. As luck would have it, I recently loaned my engine stand out. Also, I just got the race bike engine cases back from being bored and was so looking forward to building it... Kinda ill timing.
 

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Check the two pressure lines from the wastegate actuator solenoid to the turbo. If either is disconnected or split, it would be possible to overboost.
 

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Discussion Starter #18
Little bit done. Got the tailgate off, trunk floor out, oil drained, and exhaust from the turbo back off. Getting a cat delete mid-pipe made. Still pretty limited as to what I'm able to physically do with the new shoulder.
 
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