REPLACED ENGINE STILL OVERHEATING

[WT2002CARS]

Welcome to my nightmare. I have owned a 1999 LOTUS ESPRIT V8 TWIN TURBO for 3 years now and its spent the last 3 years in the workshop.

Rebuilt last engine twice and kept spewing coolant out of header tank when the Turbo's engage. My last engine blew up on the highway due to spewing and finally cracked block. $20,000 down the drain.

So I bought another engine for $15,000 all good and even replaced head gaskets took it out for road test and deja Vu when the turbos engage it spews coolant out of header tank.

Can someone please advise and we bled the system, water pump ,radiator hoses all good, New Stat only thing not changed is header tank and cap.

So totally fed up now spent over $35,000 and still no joy. Please help !!!! 

[silverfrost]

That is pants news and sorry to hear your dramas with the car.  A few guys will hopefully chime in who know the lotus v8 engine quite literally inside out. 

Maybe send Mike Sekinger on these forums a pm as he would be one of the first folks I would seek advise from on your engine if it was me.

Also did you have the cylinder heads crack tested on the rebuilds ? Also what cylinder head gaskets did you use ? 

I wish you luck on finding out what drama you seem to be having, as nothing worse than throwing money at a repeating problem, also are the turbos standard and what boost are you running ? 

Also have you forced water through the front radiator to make sure that's it's not blocked, also is the coolant flowing back to the header tank through the return pipe ? As these can block up on cars giving the same symptoms as severe  overheating and can be wrongly diagnosed as head gasked failureally sometimes. 

[Dan E]

Puts my oil leak into perspective. Best of luck my friend someone on here will know the answer keep the faith 

[mike_sekinger]

Hi Wayne,

What had dreadfully situation for you. It is crazy that you have never been able to establish a reliable running engine.  You must be so frustrated !

You need to work systematically through some fundamental checks to rule out potential major faults.  You mention that the problem is at higher engine speeds, so assuming that the engine idles without the problem?

No point in thinking too much about the previous engine as it is long dead.   Let's start with the current engine: Where did it come from? - meaning it is proven in any way?

- If you are in any way unsure, run a compression test of all cylinders and check for unwelcome gases in the coolant (just to rule out HG)

- Flow test the coolant circuit through the radiator (just simulate the water pump and check the return)

- Pressure test coolant system ( I have a tool for this with a modified thermostat housing if you want to borrow it)

Let's hope the answers with guide the next necessary steps.

EDIT: Did you ever establish that you have correct boost control?   I remember your thread from some time ago, but there was never any confirmed resolution.

Cheers,

Mike S

[WT2002CARS]

Thanks Guy's,

My Tech is about to burp the system and do a pressure test.

Fingers crossed.

[mike_sekinger]

Did you ever resolve why you were running high boost and in fact what that level of boost was?

[gmendoza]

The fact you replaced the head gaskets on the new engine is a huge red flag. See my thread about head gaskets.

Check for combustion gases in the coolant through the header tank connector for the hose to the overflow tank when the overflow tank is bubbling, If you do, then head gaskets are the issue. 

[Vulcan Grey]

I 2nd pressure testing the cooling system (as a first step)!  If the cooling system cannot hold 21psi, then the coolant will boil prematurely, and get pushed out the overflow, and the engine will over heat...  The $15 coolant pressure cap can cause the engine to fail...!

 

Then check coolant flow through the system (as Mike mentioned).

The V8 system is difficult to bleed the air out of, so a vacuum filler would help (airlift tool).

 

 

[WT2002CARS]

Thank you so much for help guys, so far my mechanic has noticed my car is not blowing any heat into the car. So far it appears heater control valve may be seized so fingers crossed. I'll keep you posted. 

[HowardRoark]

Hi Wayne,

I have a lot of empathy for you buddy!!   Hang in there.     My Update:  V8 Head Gasket sizing issue.

I also just had a head gasket fail after 1,000 miles, with coolant leaking.  My tech couldn't believe the failure, because he is a very accomplished Lotus tech here in San Diego, and he has rebuilt hundreds of engines.   He took off the older V8 gaskets and measured them.   He got some new head gaskets from SJ Sportscars (I believe), and I think he said the new ones were perhaps 2 mm difference in size, and that the new ones were in fact the correct size, according to OEM spec. 

So here is a question for all of the recent V8 head gasket failures - are you sure that your gasket is the OEM size and spec?   My engine is now back together and I have put a couple hundred miles on it, so good so far.   I will keep you updated but the engine is performing well after the switch in gaskets.  I think that SW Lotus Centre is also marketing a new gasket that is done to the original Lotus OEM specs.    Hopefully that is a cure to these failures. 

Cheers

[WT2002CARS]

I'm glad your fixed up but I have just changed the head gaskets and my overheating occurs as soon as the turbo's engage. I'm hoping mine is an air lock or blockage somewhere. Cheers

[Barrykearley]

Turbos are water cooled - sounds like a blockage in the system.

undo the bleed nut on top of the road until water of the hot variety comes out - then check the hose the other side

[WT2002CARS]

Finally it turns out the aftermarket Head gaskets were total crap. My engine was rebuilt three times and finally blew up due to overheating.  $30,000 later and installed a replacement used engine which I had replace head gaskets again. I went with OEM head gaskets and finally its not overheating Very expensive lesson learned. Also JAE has discontinued selling the aftermarket head gaskets.

However when driving at low speed the engine seems a little lumpy and hesitant and labors. If you put your foot down it will go from hesitating to absolutely flying like it should. Btw idles just fine. Any  ideas please? Everything replaced leads,plugs except fuel injectors. Other than that if I drive it hard it is the beast it should be. Thanks. 

[superdavelotus]

I had a similar problem and it turned out to be faulty wiring to the O2 sensors due to engine in and out. I think the ECU was reading the wrong sensor so kept correcting itself. So on idle and cruising it would run lumpy. When you put you foot down, the WOT would override the ECU and the car would fly. Check out the O2 readings on a live data and they all should be fluctuating not static.

[WT2002CARS]

Thanks for the advice Dave, do you are anyone know the best place to get a scan tool ?