Chargecooler pump
Discussion
Well at 26K miles my chargecooler pump is a little round wheel. I was going to put in a electric pump put have just rebuilt my mechanical one. I use to many accesories (stereo amp, A/C blower, and lights.) The charging is pretty limited as it is and I'm not sure the alternator can handle much more. So after much thought I have reconsidered and kept the mechanical pump. Only 26K and all the vanes have broken off the chargecooler pump. Oh well it was a fast fix at 2hrs. I have to descale the inside of the header tanks tomorrow.
Calvin 90 SE
Calvin 90 SE
If you want to play it by the book the manual says to remove the pump and visually check the impeller at 18K miles, replace as needed. I kind of laughed at that one too. The way I check it is, after a robust drive at higher rpm with the turbo engaged frequently pull over, quickly open the engine compartment, and put your hand on the orange box that has Lotus Chargecooler on it. If it is cool enough to to keep your hand on it the impellers are still circulating coolant. If your hand has the words Lotus Chargecooler burned into the skin it's time to change pump. (Old SE joke) Just kidding it doesn't get that hot. It normally should be just above ambient air temps or warm. After it idles for a minute or two the box will get hot as the pump slows down and the box heat soaks (pump rotates at the speed of a distributor on older cars). Now all this means is that you have at least some impellers left and it is still circulating coolant, not that all the impellers are in fine condition with max flow. The pumps have 10 rubber vanes and even as little as 2 vanes will move coolant. With a broken impeller the turbo will not hold max boost as long also before it backs down. A second or two compared to a longer sustain before it backs down. This hard to tell unless you have driven an SE with the pump working properly. Even if you have driven one with an excellent chargecooler the degradation in performance is over a period of time. It will feel like a non SE car but how many other SE's can you drive to compare yours with? But the car is still very quick as many pre SE owners will attest, to many it will appear the car is working fine. Roy from the SF club, just told me a story about an SE for sale that had been identified with a broken pump at pre sale inspection and was fixed as a condition of the sale. After the owner fixed it he almost did not want to sell it because the car was much faster. Sanj also made some sort of comment about the neoprene rubber the impellers are made of do not withstand temps below 45F well and may accelerate the failure below this temp.
Calvin 90 SE
Calvin 90 SE
I just recently purchased a ’91 SE and it had a bad charge cooler pump. Calvin is correct with his advise on a by-the-book replacement and maintnenace. However, when I was faced with this replacement I took one look at where the stock pump is sitting and said to myself there has got to be a better way. So, I ended up going with Andy Whittaker’s advise. I disconnected the stock mechanical pump, left it in place, and replaced its function with an electrical marine circulation pump. I think that this is the way to go. The installation is simple. The pump that I found is cheep ($27 USD), quiet, small, very serviceable, and I suspect pumps a lot more water than the stock mechanical pump (750gph). I don’t have any details or photos with me today. I’m at work at the moment. But if you are interested in the details of this project just e-mail me at walter.c.deane@usace.army.mil. I will try to round up info on the pump supplier, and maybe shoot you some photos.
Walt
Walt
Walt,
You can buy a block off plate for the pump. After a while the pump seals on the shaft will go out from not being in contact with fluid on the pump side. The block off plate can be had from SJ. The block off plates are used in 89 non chargecooled with AC Delco ignition. It is not something that needs attention right away. It will make a lot of noise after a while that will be annoying. I had to go with the mechanical pump for now as my alternator has been putting out less than stellar output. I think my stereo power amp, use of blowers for A/C, and lights at night aggravate the problem.
You can buy a block off plate for the pump. After a while the pump seals on the shaft will go out from not being in contact with fluid on the pump side. The block off plate can be had from SJ. The block off plates are used in 89 non chargecooled with AC Delco ignition. It is not something that needs attention right away. It will make a lot of noise after a while that will be annoying. I had to go with the mechanical pump for now as my alternator has been putting out less than stellar output. I think my stereo power amp, use of blowers for A/C, and lights at night aggravate the problem.
The temp difference of the chargecooler box was indeed dramatic. Very cool to the touch and my BOV is working perfectly. I put in new Mintex pads and painted the brake calipers the same red color as the body using hi temp paint. It looks good looking through the chrome Ruote wheels. The first caravan of up 12 cars will be leaving the Minneapolis/St. Paul area for the 2002 LOG today (North American Lotus Owners Gathering). They will be taking the long way there along the twisties and rolling hills of the river valley. I will be in the second Caravan leaving Friday morning.
Calvin 90 SE
Calvin 90 SE
Gassing Station | Esprit | Top of Page | What's New | My Stuff