Replacing the Timing Belt on a '84 Lotus Turbo Esprit


My advice has always been to check the timing belt and replace it whenever it looks worn or the maintenance schedule recommends it, whichever is sooner. I realize that replacing the belt is not an easy task and can be very expensive. But if the belt should happen to go, you will send valves and pistons on a collision course that will test the stratospheric limits of your bank account. Pistons can cost upwards of $1200US a piece! For this reason, I have always considered the timing belt replacement as an insurance policy.

However, since about 1995, Lotus has started using a new timing belt that is supposed to be good for 100K miles. The interesting thing is that the manual says that you're supposed to replace it every 3 years or 36K miles, unless you live in California. The maintenance schedule says that California cars should have their belts replaced every 100K miles regardless of age. Keep in mind that cars that used the older belt recommended that you change it every 25K miles during your "C" service.

The thing is that the new belt is the same in all markets, so there unless there is something special about the California smog that makes the rubber last longer, replacing it prematurely may turn out to be a waste of money. Also, the old belt is no longer available, so my assumption is that once the belt in an older car has been replaced with the new style belt, you could follow the new maintenance schedule. I asked my friendly Lotus-certified mechanic about this and he agrees. He says you should inspect the belt very often and adjust the tension if necessary, but don't replace it unless it shows signs of wear.

Adjusting the timing belt tension is a critical part of the replacement process. Proper tension for the Esprit is 95 lbs. To measure it, you can use the $500+ Lotus Boroughs Gauge. If you don't want to spend quite that much money on a tool you only use once every 8 to 10 years, there is an alternative. The timing belt's manufacturer, Gates, sells a tool called the Krikkit 1 that will do the job and only costs about $11US. A friend has compared the readings from this gauge with those from the Lotus, Porsche, and Ferrari gauges and has found it to be just as accurate.

Esprits with the V8 engine have a different process for measuring belt tension. These cars use a new electronic tension gauge that use the vibration of the belt and actually uses frequency as its unit of measure.

I had my timing belt replaced on my SE. Regardless of what you may have heard, it is not necessary to remove the engine to change the belt. Labor for the job was 10 hours at $45/hour.  

A long time ago Jim J Seippel documented the procedure for replacing the timing belt on his 84MY Turbo Esprit. It was the first procedure that was documented in the Esprit Fact File. It doesn't have the fancy pictures that other procedures here have. So if someone wants to take the task of taking photos of the process the next time they change their belt, I will gladly add them to this page.

Please note that the procedure here is for a 1984 Turbo Esprit. It should work for other models of the same vintage, but always consult with the proper service manual for your model year when tackling such a complex task.

On a Difficulty Scale of 1 to 10, this procedure rates a 9.



I did not have the service manual and just replaced the timing belt on my '84 Turbo Esprit. The job took about 4 hours, but I could do it in about 2.5 hours the next time. I found several problems that might cause difficulty to anyone attempting this task. I wanted to share the process that I used in case anyone else wants to try this themselves. I am writing this procedure from memory 2 days after I finished the job so there may be minor omissions. I wish that I had the manual, but they are slow in getting off back order.

I have a lift, so belt replacement was not back breaking. However, this task can be done on jack stands. Before you start, there are 2 items that you need that are not part of most tool boxes, white-out and lock wire. The purpose for these items will be apparent later. These instructions apply to an '84 Turbo, so if you try this on a different model, you might have to modify these instructions.

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  1. Drain the cooling system by loosening the radiator drain (right hand side of the radiator).

  2. From the top of the car inside the trunk, remove the engine cover, the air duct (attached to the left side of the engine compartment by two 6mm bolts and a screw) and the radiator cap (the radiator cap allows the cooling system to finish draining).

  3. Loosen the lower alternator adjusting bolt, and remove the nut at the front side of the alternator pivot. Push down on the alternator so that the belt is loose.

  4. Remove the thermostat housing - loosen the hose clamps on both ends of the hose that attaches to the thermostat housing and remove the two 8mm bolts that attach the thermostat. Carefully twist the hoses and the thermostat housing until you have it in your hands.

  5. Loosen and remove the heater hose that attaches in front of the cam pulleys.

  6. From the bottom of the car, remove the bottom engine cover plate and set it aside.

  7. Turn the crankshaft pulley attaching bolt using a 19 mm socket on the end of a pull bar and rotate the crankshaft clockwise until the pull bar touches the frame. Now bump the starter by using the ignition switch or by shorting the starter terminal on the solenoid if you are familiar with the procedure. The starter turns the engine in the correct direction to loosen the crankshaft pulley attaching bolt.

  8. From the bottom of the car, turn the crankshaft pulley using the pull bar as if you were tightening the bolt. You must position the pulley where the timing mark on the pulley aligns with the marks on the housing above the pulley. You can use a mirror or use your finger nail to determine if the marks line up. Use the top timing mark - this is TDC.

  9. From the top of the car, check the 2 camshaft pulleys to see if the timing marks align. There should be marks on the intake and exhaust pulleys and they should be next to each other. If you were to lay a straight edge between the center of the intake and exhaust cams, the marks would fall on this line. There should also be a mark on the oil pump/distributor shaft drive pulley that should be at the top of the pulley. If the marks are not where they are supposed to be, crawl under the car and rotate the crankshaft one full revolution. Climb back into the trunk and check for the marks. In my case, the intake pulley had three marks - two blue marks about 180 degrees apart and one red mark 90 degrees between the blue marks. The exhaust cam pulley and the distributor drive pulley did not have any marks. If your marks are aligned correctly, recheck the crank mark and then use the white-out to make the correct marks easy to find. If you do not have standard marks like my engine, make sure that the crank pulley mark aligns with the timing mark for TDC (the upper mark) and then use the white-out to mark the edge of the teeth on the cam pulley that are closest to each other. Also, put a small mark on the edge of the uppermost tooth on the distributor pulley. Now you have marks that you can use, so there is no excuse for bending valves.

  10. Remove the crankshaft pulley bolt taking care not to allow the crankshaft to rotate. I used sharp blows with my hand to loosen the bolt again. It shouldn't be very tight since you have only turned the engine over a couple of times since you first loosened the bolt.

  11. Now loosen the vacuum pump belt adjustment and the air conditioning belt adjustment and remove all three belts.

  12. Now you can remove the crankshaft pulley by pulling it toward the front of the car.

  13. Remove the triangle bracket that is attached between the lower alternator bolt and top edge of the timing belt tensioner. There is a third bolt attaching the bracket to the upper engine, but you should be able to remove the bolt from below.

  14. Disconnect the front cooling system hose and the other heater hose at the front of the engine. These hoses will be in the way when you remove the timing belt.

  15. Remove the timing belt tensioner. - Loosen the adjustment on the tensioner by turning the adjusting screw counter clockwise. Now remove the uppermost tensioner attaching bolt. Underneath the washer on this bolt there is a small hole that is used to lock the tensioner back. Compress the tensioner with your hands and insert a large paper clip into the lock hole on the tensioner to hold the tensioner compressed. The paperclip should engage a groove on the tensioner plunger and keep the tensioner compressed. Now remove lower attaching bolt and then remove the tensioner. This sounds easier than it actually is since the tensioner is still mostly too big. With patience, the tensioner will fall out into your hands.

  16. Now remove the timing belt by pulling it to the front of the engine and snaking it around the water pump and hoses that are still attached to the engine.

  17. Put the new timing belt on the engine by snaking it around the obstacles on the engine using the reverse of the moves that you used to remove it. Be careful not to kink the belt or otherwise damage it. Slide the belt onto the intake pulley under the "L" shaped safety bracket and then slide the belt over the exhaust pulley. From the bottom - keep the belt tight between the exhaust cam pulley and the crankshaft pulley and slide the belt over the crankshaft pulley. The Belt should not have any slack between the exhaust pulley and the crankshaft pulley.

  18. Now get your significant other or a sober friend to sit in the trunk and watch the marks for you. Put the belt over the distributor pulley and make sure that there is no slack between the intake and the distributor pulley. You should have the belt installed at this point with all of the slack between the distributor pulley and the crankshaft pulley and all of the marks should line up. You should slide the crank belt pulley back on the crankshaft to check the crank timing mark.

  19. Now take the tensioner and loosen the adjustment until the adjustment screw has only one or two threads engaged. Use the lock wire and loop a piece around the edge of the fork that supports the idler pulley. The wire goes between the pulley and the fork. String the lock wire around the boss that the lower alternator adjusting bracket bolt screws into and tighten the lock wire until the tensioner is completely compressed. If you do not do this, the tensioner will not be able to be reinstalled since it will be expanded and will be bigger than it's mounting location. An alternative procedure is to use a large paperclip inserted into the small hole next to the upper mounting bolt hole. The paperclip must engage the groove on the tensioner plunger. Either method to keep the tensioner compressed is acceptable. I like the lockwire method because it is possible to compress the tensioner more.

  20. Now reinstall the tensioner and replace the two screws by sliding them into place and tightening them a turn or two. Check all four timing marks again by sliding the crank pulley back on the crankshaft and checking the position of the crankshaft. Now ask your helper to check the other marks. Cut the lock wire and remove it taking care not to damage the new timing belt.

  21. Remove the crank pulley and tighten the lower and upper tensioner attaching bolts. Then tighten the tensioner adjustment using a 13mm open end wrench. You can check the free play in the tensioner by deflecting the belt between the exhaust cam and the crankshaft. I adjust the tensioner until there is about 1/8th inch of free play in the tensioner checked between the pulley bracket and the tensioner body. Tighten the locknut on the tensioner adjustment using a 15/16 inch box end wrench. I happened to have a cheap wrench in my toolbox that was shorter than the normal wrench and fit perfectly.

  22. Now reinstall the crankshaft pulley and bolt and turn the engine over by hand 2 full revolutions until the crankshaft pulley timing mark aligns. Ask you helper to check the timing marks on the cam pulleys and on the distributor pulley. If the marks align perfectly, check then yourself. If you don't check them yourself and they didn't line up and you bend something, you might wind up in divorce court. If all of the marks line up, pat yourself on the back, you are close to being finished. If they don't line up, say a few curse words and then remove the tensioner and position the marks correctly, then go back to step 19.

  23. Remove the crank pulley and attach the triangle bracket by sliding it over the alternator pivot bolt and start the lower bolt that attaches the triangle bracket and lower alternator adjustment bracket to the tensioner. Start the upper bolt and tighten the two bolts.

  24. Reconnect the front cooling system hose and the other heater hose at the front of the engine. Tighten the hose clamps.

  25. Install the crank pulley and tighten the bolt (don't worry if the bolt is not tight enough). Install the AC belt and vacuum pump belt and tighten the adjustments. Install the alternator belt. If the belt are worn, now is a good time to replace them.

  26. From the top side, adjust the alternator belt tension and tighten the adjusting bolt. Replace the nut on the alternator pivot and tighten the nut.

  27. Replace the front heater hose in front of the cam pulleys and tighten the clamp.

  28. Replace the thermostat housing gasket and replace the thermostat housing and tighten the bolt and the hose clamps.

  29. Replace the air duct on the left side of the engine compartment.

  30. Put the car in first gear and have someone hold the brakes while you tighten the bolt on the crank pulley.

  31. Make sure that all of your tools are clear and that there is nothing that can get caught in the engine. Start the engine and allow it to run for about ten seconds to be sure that it starts and that there are no problems before you add coolant.

  32. Make sure that the coolant drain plug is installed and put coolant back into the engine. Open the bleeder screw and let out any trapped air.

  33. Reinstall the lower engine plate, set the ignition timing and replace the top engine cover and you are finished.

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By Jim J Seippel


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